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23 tháng 2 2021

tôi ko bt

23 tháng 2 2021

a) 5m3 = ......5000.......dm3                                    7,5m3 = .........7500............ dm3

7m3 = .......7000000..........cm3                                     8,6 m3 = ........8600000...........cm3

26m3 = ......26000........dm3                                     0,4m3 = ........400.............dm3

b) \(\frac{7}{4}\) m3 = .....1750..........dm3                        \(\frac{1}{5}\) m3 = ......200000..............cm3

23 tháng 2 2021

Sau ba giờ ô tô chạy được số phần của quãng đường là:

            3/8 x 2/9 x 4/2 = 24/144 (quãng đường)

                   Đáp số: 24/144 quãng đường

23 tháng 2 2021

                                                                                          Bài giải

                                                    Sau 3 giờ ô tô đó chạy được số phần quãng đường là:

                                                                    3/8 + 2/9 + 4/2 = 187/72 ( phần )

                                                                                        Đáp số: 187/72 phần quãng đường

vote cho mình với

Câu 1:Tìm danh từ, động từ, tính từ trong các câu văn sau:    Trăng đêm nay sáng quá! Trăng mai còn sáng hơn. Anh mừng cho các em vui Tết Trung thu độc lập đầu tiên và anh mong ước ngày mai đây, những Tết Trung thu tươi đẹp hơn nữa với các em.Cau 2: Mỗi câu hỏi dưới đây được sử dụng với mục đích gì?a, Có gì quý hơn gạo?b, Thế mà được coi là giỏi á?c, Sao chau bà Ngoan thế nhỉ?d, Anh...
Đọc tiếp

Câu 1:

Tìm danh từ, động từ, tính từ trong các câu văn sau:

    Trăng đêm nay sáng quá! Trăng mai còn sáng hơn. Anh mừng cho các em vui Tết Trung thu độc lập đầu tiên và anh mong ước ngày mai đây, những Tết Trung thu tươi đẹp hơn nữa với các em.

Cau 2: 

Mỗi câu hỏi dưới đây được sử dụng với mục đích gì?

a, Có gì quý hơn gạo?

b, Thế mà được coi là giỏi á?

c, Sao chau bà Ngoan thế nhỉ?

d, Anh vặn giúp cái đài nhỏ hơn... được không?

e, Bác đi làm về đấy ạ?

Câu 3: 

Nêu tác dụng của dấu gạch ngang trong đoạn văn sau:

a, Tuần trước, vào một buổi tối, có hai người bạn học cũ đến thăm tôi: 

Châu- (1) họa sĩ và Hiền- (2) kĩ su một nhà máy cơ khí. Châu hỏi tôi:

-(3) Cậu có nhớ thầy Bản không?

-(4) Nhớ chứ! Thầy Bản dạy vẽ mình hổi nhỏ phải không?

b, Đảo Khỉ là khu bảo tồn loài khỉ. Khách đến tham quan Đảo Khỉ cần thực hiện điều quy định dưới đây:

-(1) Mua vé tham quan trước khi lên đảo.

-(2) Không trêu chọc thú nuôi trong chuồng.

-(3) Không chó thú ăn loại thức ăn lạ.

-(4) Giữ gìn vệ sinh chung trên đảo

help mee

11
23 tháng 2 2021

1000 -10001 

23 tháng 2 2021

dễ mà sao ngu thế !!!!!!!

22 tháng 2 2021
Câu hỏi ngu ngốc quá đi ai mà dải được🤮
22 tháng 2 2021
!!!!!!!ngu 🤮🤮🤮🤮🤮🤮🤮🤮🤮🤮🤮🤮🤮🤮🤮🤮🤮vây mà đố
22 tháng 2 2021

S A B C D K

gọi K thuộc SC sao cho DK ​​\(\perp\) SC , BK \(\perp\)SC

=> ((SCD),(SBC)) = (DK,KB)

tính được SD = \(\frac{\sqrt{10}}{2}\)a, AC = \(\sqrt{3}\)a, SC= \(\frac{3\sqrt{2}}{2}\)a

\(DC^2=SD^2+SC^2-2SD.SC.cos\widehat{DSC}\)

=> \(\widehat{DSC}\)=....... (số xấu)

\(sin\widehat{DSC}\)\(\frac{DK}{SD}\)=> DK = \(\frac{\sqrt{2}}{2}\)=BK

\(DB^2=DK^2+BK^2-2.DK.BK.cos\alpha\)=> \(\alpha=\frac{\pi}{2}\)

22 tháng 2 2021

quản lí hỏi để thử tài học sinh à

22 tháng 2 2021

Hai mặt phẳng (AB′D′)(AB′D′) và (A′C′D)(A′C′D) có giao tuyến là EFEF như hình vẽ.

Hai tam giácΔA′C′D=ΔD′AB′ΔA′C′D=ΔD′AB′và EFEF là đường trung bình của hai tam giác nên từ A′A′ và D′D′ ta kẻ 2 đoạn vuông góc lên giao tuyến EFEF sẽ là chung một điểm HH như hình vẽ.

Khi đó, góc giữa hai mặt phẳng cần tìm chính là góc giữa hai đường thẳng A′HA′H và D′HD′H.

Tam giác DEFDEF lần lượt cóD′E=D′B′2=√132D′E=D′B′2=132,D′F=D′A2=52D′F=D′A2=52,EF=B′A2=√5EF=B′A2=5.

Theo hê rông ta có:SDEF=√614SDEF=614. Suy raD′H=2SDEFEF=√30510D′H=2SDEFEF=30510.

Tam giác D′A′HD′A′H có:cosˆA′HD′=HA′2+HD′2−A′D′22HA′.HD′=−2961cos⁡A′HD′^=HA′2+HD′2−A′D′22HA′.HD′=−2961.

Do đóˆA′HD′≈118,4∘A′HD′^≈118,4∘hay(ˆA′H,D′H)≈180∘−118,4∘=61,6∘(A′H,D′H^)≈180∘−118,4∘=61,6∘.

12 tháng 5 2021

D là hình chiếu vuông góc của D'D trên (ABCD)(ABCD).

\Rightarrow \Delta ACDΔACD là hình chiếu vuông góc của \Delta ACD'ΔACD trên mặt phẳng (ABCD)(ABCD).

Do đó \cos \alpha = \dfrac{S_{ACD}}{S_{ACD'}}cosα=SACDSACD với \alphaα là góc cần tìm.

Ta có \left\{ \begin{aligned} & DA^2 + DC^2 = 3\\ & DC^2 + DD'^2 = 4\\ & DA^2 + DD'^2 = 5\\ \end{aligned}\right. \Leftrightarrow \left\{ \begin{aligned} & DA^2 = 2\\ & DC^2 = 1\\ & DD'^2 = 3\\ \end{aligned}\right.DA2+DC2=3DC2+DD2=4DA2+DD2=5

22 tháng 2 2021

Hai mặt phẳng (AB′D′)(AB′D′) và (A′C′D)(A′C′D) có giao tuyến là EFEF như hình vẽ.

Hai tam giác ΔA′C′D=ΔD′AB′ΔA′C′D=ΔD′AB′ và EFEF là đường trung bình của hai tam giác nên từ A′A′ và D′D′ ta kẻ 2 đoạn vuông góc lên giao tuyến EFEF sẽ là chung một điểm HH như hình vẽ.

Khi đó, góc giữa hai mặt phẳng cần tìm chính là góc giữa hai đường thẳng A′HA′H và D′HD′H.

Tam giác DEFDEF lần lượt có D′E=D′B′2=√132D′E=D′B′2=132, D′F=D′A2=52D′F=D′A2=52, EF=B′A2=√5EF=B′A2=5.

Theo hê rông ta có: SDEF=√614SDEF=614. Suy ra D′H=2SDEFEF=√30510D′H=2SDEFEF=30510.

Tam giác D′A′HD′A′H có: cosˆA′HD′=HA′2+HD′2−A′D′22HA′.HD′=−2961cos⁡A′HD′^=HA′2+HD′2−A′D′22HA′.HD′=−2961.

Do đó ˆA′HD′≈118,4∘A′HD′^≈118,4∘ hay (ˆA′H,D′H)≈180∘−118,4∘=61,6∘(A′H,D′H^)≈180∘−118,4∘=61,6∘.

12 tháng 5 2021

Gọi NN và PP lần lượt là trung điểm của SASA và ABAB.

Theo tính chất đường trung bình trong tam giác ta có NP // SBNP//SB và PC // AMPC//AM.

Suy ra \alpha = \widehat{NP, PC}α=NP,PC.

Ta có NP = \dfrac{SB}2 = \dfrac{\sqrt5}2NP=2SB=25 và PC = AM = \sqrt 5PC=AM=5;\\ NC = \sqrt{NA^2 + AC^2} = \sqrt{\dfrac14 + 8} = \dfrac{\sqrt{33}}2.NC=+=41=233.

\Rightarrow \cos \widehat{NPC} = \dfrac{NP^2+PC^2-NC^2}{2.NP.PC} = \dfrac{\dfrac54 + 5 - \dfrac{33}4}{2.\dfrac{\sqrt5}2.\sqrt5} = -\dfrac25cosNPC=2.NP.PCNP2+PC2

22 tháng 2 2021

Ta có {BC⊥ABAB⊥SC⇒AB⊥CE{BC⊥ABAB⊥SC⇒AB⊥CE

Khi đó {CE⊥ABCE⊥SA⇒CE⊥(SAB){CE⊥ABCE⊥SA⇒CE⊥(SAB)

Áp dụng hệ thức lượng trong tam giác vuông ta có: SC2=SE.SB⇒SESB=SC2SB2SC2=SE.SB⇒SESB=SC2SB2, tương tự SDSE=SC2SA2SDSE=SC2SA2

Lại cả CA=AC√2=2a;VS.ABC=13SC.SABC=23a3CA=AC2=2a;VS.ABC=13SC.SABC=23a3

Khi đó VS.CDEVS.ABC=SESBSDSA=SC2SB2.SC2SA2=4648=13VS.CDEVS.ABC=SESBSDSA=SC2SB2.SC2SA2=4648=13

Do đó VS.CDE=13.23a3=2a39VS.CDE=13.23a3=2a39.

22 tháng 2 2021
Với OLM.VN

Học mà như chơi, chơi mà vẫn học

22 tháng 2 2021

+ SA⊥(ABCD)⇒SA⊥BDSA⊥(ABCD)⇒SA⊥BD (1)

+ ABCD là hình vuông ⇒AC⊥BD⇒AC⊥BD (2)

+ Từ (1) và (2) suy ra BD⊥(SAC)⇒BD⊥SCBD⊥(SAC)⇒BD⊥SC

22 tháng 2 2021
Mình không biết.
ĐỀ SỐ 1 B.USE OF LANGUAGE: Question II. Find the word which has different sound in the part underlined.(1 point)                                                                                                                                            1. A. wanted                            B....
Đọc tiếp

ĐỀ SỐ 1

 

B.USE OF LANGUAGE:

Question II. Find the word which has different sound in the part underlined.

(1 point)                                                                                                                                           

1. A. wanted                            B. washed                               C. decided                   D. needed

2. A. fun                                     B. sun                                 C. surf                           D. cut

3. A. leisure                            B. eight                                 C. celebrate                   D. penalty

4. A. A. although                    B. laugh                                  C. paragraph               D. enough

Question III. Choose the best answer. ( 2.0 points )

1. The Gong Festivals is held ____________  in the Central Highlands.

A. year                        B. yearly                                 C. annual                                 D. annually

2. YMoan was the greatest pop singer of the  ____________ group in Dak Lak Province.

A. Tay ethnic              B. Thai ethnic                         C. Ede ethnic              D. Muong

3. He was called  “____________ singer of the great woods”.

A. the                          B. a                                          C. an                                        D. the best

4. Teenagers enjoy listening to music and____________  out with friends.

A. hang                                   B. to hang                               C. hanging                              D. hangs

5. Life in a small town is ____________ than that  in a big city.

A. less peaceful                       B. much more peaceful    C. much peaceful             D. peaceful

6. My mother always tells me that I ___________  be home by 9 p.m.

A. has to                      B. have to                    C. have not to                          D. mustn’t

7. When you eating in India, you_______ use the right hand. Never use the left hand.

A. must                                   B. should                     C. shouldn’t                      D. mustn’t

8. ____________ month is the Hoa Ban Festival of the Thai people held in?

A. Which                   B. When                                   C. How many                    D. However

Question IV. Give the correct form of the words in brackets: ( 1.0 point)

1. She   ____________   wear that costume because it’s the family tradition.              (have to)

 

2. In India, you ______ shake hands with women, especially in rural ereas. It’s a taboo.

(must)

3. The wai is the __________   greeting of people in Thailand.                           (tradition)

4. In Australia, you mustn’t ___________   on a person’s accent.                         (comment)

C-READING:

Question V: 1. Read and complete the passage with words in the box. (1.5 point)

          

In addition                     Also                          As I have noted

In my opinion                Besides                                 I think

My favorite leisure activity is listening to music.(1)_____________, listening to music not only helps me relax but also provides me with musical knowledge. I (2)________ like the time that I can lie lazily in bed, put on the small earphone with my iPod and enjoy any favorite songs of many kinds of music: pop, hip-hop, rock or jazz. I like pop music very much because I think it is gentle and suitable for teenagers. I listen to rock music when I am sad and after that I feel cheerful and happy. (3)________________ music from other countries is also good for teenagers to understand other cultures. (4)________ that, the lyrics are easy to understand and interesting. (5)________, it can improve my English and listening skills. (6)___________, music is an important part of my life and it helps me love my life more.

2. Read the passage and answer these questions below. (1point)

After retiring, my uncle – a lover of the sea- took up a strange leisure activity : he spends most mornings at the beach, looking for things that the sea sends ashore. He says: It’s a multi-beneficial leisure activity. I can get some exercise, blending, picking up, and walking. I can breathe the fresh air and enjoy the vastness and quietness of the sea. Sometimes I watch the children playing beach games and I feel years younger. At the same time, I can also clean the beach. It’s volunteer work, isn’t it? Many of the things I pick up from the beach are still useful to someone. I clean them and sell them at the Sunday flea market in the town nearby. Do you know of any leisure activity that pays? Mine does!

 

1. When did the writer’s take up this strange activity?

- ………………………………………………………………………………………..

2. Which part of the day does he go to the beach?

-………………………………………………………………………………………..

3. How does he feel watching the children playing beach games?

- ……………………………………………………………………………………….

4. What kind of volunteer work does he do?

-……………………………………………………………………………………..…

D-WRITING:

Question VI. Make sentences, using the words and phrases provided (1.5point)

1. Tippping/ not/ custom/ Viet Nam/ so/ you/ not/ have/ tip/ if/ don’t want.

………………………………………………………………………………………………

2. In Brazil/ standard/ tip/ in/ restaurant/ be 10 percent.

……………………………………………………………………………………………….

3. The xoe dance/ performed/ the boys and girls/ the hamlets.

………………………………………………………………………………………………

4. We/ have/take/ shoes/ when/ we/ inside/pagoda.

……………………………………………………………………………………………….

5.Nowadays/ teenagers/ rely/ technology/ than/ the/ past.

………………………………………………………………………………………………..

6.Life/ the countryside/ changed/ a lot/ the/ ten /years.

…………………………………………………………………………………………

 

ĐỀ SỐ 2

 

Question I. Find the word which has different sound in the part underlined. ( 1 point)                                                                                                                                           

1.         A. mention                 B. question                 C. action                     D. education

2.         A. listened                B. opened                      C. wanted                    D. lived

3.         A. community            B. computer                C. museum                 D. customs

4.         A. needed                  B. opened                      C. wanted                    D. decided

Question II. Choose the best answer A, B, C , or D to complete the sentences. (2. 5 points)                                                                                                                                           

1. You should ____________  information about a custom or tradition.

A. finds                              B. found                     C. finding          D. find

2. A tradition is something we do that is special and ____________ down through the generations.

A. to passed

B. passed

C. passing

D. is passing

3. In the UK, there are lots of customs for table manners. For example, We ____________ use

a knife and fork at dinner.

A. have to                     B. are having                    C. has to                          D. having to

4. In Viet Nam, you____________  use only the first name to  address people older than you.

A. should                        B. must                           C. shouldn’t                      D. have to

5. At the Mid-Autumn Festival ,kids can sing, dance, and enjoy moon-cakes ; ____________, every child likes it very much.

A. However            B. Moreover                            C. Because                        D. Therefore

6. In 2010, Ha Noi____________  its 1000th anniversary.

A. celebrated                  B. commemorated               C. worshipped                D. remembered

7. Tet is an occasion for family____________ in Viet Nam.

A. visitings               B. Meeting                    C. reunions                            D. seeings

8. ____________ spring comes, many Vietnamese villages prepare for a new festival season.

A. While                   B. When                      C. Nevertheless                      D. However

9. People burn incense to show respect to their ____________ during Tet.

A. relatives                  B. ancestors                      C. friends                      D. neighbors

10. The Le Mat Festival ____________ the founding of the village.

A. worships                  B. commemorates                      C. performs         D. preserves

Question III. Give the correct form of the following verbs: ( 2.0 points)

1. Peter  ____________ ________     football yesterday.                                                    (play)

 
 

2. When I came, the whole family  _________ _____ dinner around a big dining table.  (have)

3. Children should_____________  things from adults with both hands.                          (take)

4. My father and I __________   up at 5 o’clock every morning.                                     (get)

5. They  _________________ English at the moment.                                                     ( learn)

6.We   ____________________ to Hung King Festival since last Sunday.                        (go)

7. Before leaving the dinner table, _________your son ________ ask for permission?  (have to)

8.When I  ___________ ,the whole family was having dinner around a big dining table. (come)

 

Question IV. Choose the correct word for each blank in the following passage.( 3.0 points)

Spring is a time when there are many festivals in our country. Among them, Hoa Ban Festival is the most beautiful and interesting and it takes place in Lai Chau. It is typical of the (1)………life of the Thai people. In the second lunar month of the year, when it (2) ……..warmer and hoa ban - a kind of beautiful flower in the northwest mountainous area - blossoms, Hoa Ban Festival is (3)………... This is a great time for everyone, (4) …………… for boys and girls. The boy (4)………… the most beautiful flower and gives it to his girlfriend. This is not only a time for love but also for the Thai people to (5)………..for good crops, for happiness, and express their special thanks to the Gods and (6) …………... The festival is always full of songs and prayers.

  1. A .minor                     B. cultural                       C. custom                       D. festival
  2. A. gets                         B. goes                            C. comes                        D. runs
  3. A. seen                                    B. arranged                     C. observed                    D. celebrated
  4. A. largely                    B. especially                   C. generally                    D. typically
  5. A. ask                          B. look                            C. pray                            D. call
  6. A. fathers                    B. relatives                     C. families                       D. ancestors

Question V . Combine each pair of sentences to make one sentence, using the words given in brackets. 1.Lang Lieu couldn’t buy any special food . He was very poor.                 (BECAUSE)

…………………………………………………………………………………………..…..…

2.During Tet, Vietnamese people buy all kinds of sweets. They make Chung cakes as well.(SO)

…………………………………………………………………………………………..…..…

3.The Hung King Temple Festival was a local festival. It has become a public holiday in Viet Nam since 2007.(HOWEVER)

…………………………………………………………………………………………..…..…

 

16
20 tháng 2 2021

D-WRITING:

Question VI. Make sentences, using the words and phrases provided (1.5point)

1. Tippping/ not/ custom/ Viet Nam/ so/ you/ not/ have/ tip/ if/ don’t want.

…………………Tipping is not a custom in Viet Nam, so you don't have to tip if you don't want to.………………………………………

2. In Brazil/ standard/ tip/ in/ restaurant/ be 10 percent.

………………………………In Brazil, the standard tip in restaurants is 10 per cent.……………………………….

3. The xoe dance/ performed/ the boys and girls/ the hamlets.

……………………The xoe dance was performed by the boys and the girls in the hamlets.……………………………………………

4. We/ have/take/ shoes/ when/ we/ inside/pagoda.

……………………We have to take oà your shoes when we go inside a pagoda.……………………………………….

5.Nowadays/ teenagers/ rely/ technology/ than/ the/ past.

…………………………Nowadays teenagers rely on technology more than in the past.……………………………..

6.Life/ the countryside/ changed/ a lot/ the/ ten /years.

………………………Life in the countryside has changed a lot over the past ten years.………………………………

20 tháng 2 2021

ĐỀ SỐ 2

 

Question I. Find the word which has different sound in the part underlined. ( 1 point)                                                                                                                                           

1.         A. mention                 B. question                 C. action                     D. education

2.         A. listened                B. opened                      C. wanted                    D. lived

3.         A. community            B. computer                C. museum                 D. customs

4.         A. needed                  B. opened                      C. wanted                    D. decided

Question II. Choose the best answer A, B, C , or D to complete the sentences. (2. 5 points)                                                                                                                                           

1. You should ____________  information about a custom or tradition.

A. finds                              B. found                     C. finding          D. find

2. A tradition is something we do that is special and ____________ down through the generations.

A. to passed

B. passed

C. passing

D. is passing

3. In the UK, there are lots of customs for table manners. For example, We ____________ use

a knife and fork at dinner.

A. have to                     B. are having                    C. has to                          D. having to

4. In Viet Nam, you____________  use only the first name to  address people older than you.

A. should                        B. must                           C. shouldn’t                      D. have to

5. At the Mid-Autumn Festival ,kids can sing, dance, and enjoy moon-cakes ; ____________, every child s it very much.

A. However            B. Moreover                            C. Because                        D. Therefore

6. In 2010, Ha Noi____________  its 1000th anniversary.

A. celebrated                  B. commemorated               C. worshipped                D. remembered

7. Tet is an occasion for family____________ in Viet Nam.

A. visitings               B. Meeting                    C. reunions                            D. seeings

8. ____________ spring comes, many Vietnamese villages prepare for a new festival season.

A. While                   B. When                      C. Nevertheless                      D. However

9. People burn incense to show respect to their ____________ during Tet.

A. relatives                  B. ancestors                      C. friends                      D. neighbors

10. The Le Mat Festival ____________ the founding of the village.

A. worships                  B. commemorates                      C. performs         D. preserves

Question III. Give the correct form of the following verbs: ( 2.0 points)

1. Peter  ____________played ________     football yesterday.                                                    (play)

 
 

2. When I came, the whole family  _________was having _____ dinner around a big dining table.  (have)

3. Children should______take_______  things from adults with both hands.                          (take)

4. My father and I ___get_______   up at 5 o’clock every morning.                                     (get)

5. They  ______are learning___________ English at the moment.                                                     ( learn)

6.We   ______________went______ to Hung King Festival since last Sunday.                        (go)

7. Before leaving the dinner table, _____does____your son _____have to___ ask for permission?  (have to)

8.When I  _____came______ ,the whole family was having dinner around a big dining table. (come)