1.
There are both many good things and many potential dangers in social network 
It's important for parents to teach their children how to use social media wisely
Social network is the start of bad things like cyberbullying

2.

A recent report has said that many teenagers have contacted online with strangers and it makes them feel scared or uncomfortable.

Others receive onine advertising that is inapproriate for their age.

It is important that parents should be aware of what children are doing online.

Parents should make their children understand that they respect children's privacy.
However, parents want to make sure that their children are safe.

1 interested in travelling by plane

2 15 minutes riding his bike to school

3 is made by my mother everymorning

4 take care of her little brother

5 able to speak 2 languages when he was young

6 able to play the piano

7 is played all over VN

8 to play voleyball very well when he was young

9 to go fishing when he was young

10 way to the shopping mall

over

camping

was

couldn't

percussion

takes

look after

go around 

go through

wind

how long

for

do

chụp từng trang 1 thôi rồi mình giúp :)

8.a) introduce

b) before

c) doing

d) myself

e) Excuse

f) meet

g) Let

Exericse V:

31. B

32.C

33.C

34.A

35.D

Exercise VI:

36. A

37. D

38. C

39. C

40. C

Exercise VIIz;

41. D. time enough \(\rightarrow\)enough time

42. C. rises \(\rightarrow\) is rising

43. C. isn't telling \(\rightarrow\) don't tell

44. C. with \(\rightarrow\) \(\varnothing\)

45. C. taller \(\rightarrow\) tallest

Exercise VIII"

46.D

47.A

48.C

49.B

50.A

khó à nha...