Topic 2: Healthy Living for Teenagers

Teenagers should live healthily to stay strong and happy. First, they should eat more fruits and vegetables because these foods are good for their health. They should also drink enough water every day and get enough sleep at night. Second, regular exercise is very important. Teenagers can go jogging, play football, or ride a bike with their friends. Finally, they should not spend too much time using their phones or eating fast food. If teenagers follow these healthy habits, they will have more energy and feel better every day.

1. 

My sister loves painting. She paints every weekend in her room. She likes to use bright colours and paint flowers and animals. Sometimes, she goes to art classes to learn new techniques. Her favourite colour is blue, so she often paints the sky. Her paintings are very beautiful. I enjoy watching her paint because she is very creative and happy when she is working on her art.

2. 

There is some advice on how to stay healthy. First, you should eat good food. Eat fruits and vegetables every day and drink plenty of water. Second, exercise is important, so try to walk or play sports for 30 minutes. Finally, sleep well at night to feel good in the morning. It is also good to be happy and spend time with friends and family. Follow these tips to stay healthy and strong!

3. 

Hi Thấu,

There are good things. Last summer, I did some volunteer activities. I helped clean the park in my neighbourhood. We picked up trash and planted flowers. It was fun to work with my friends and meet new people. I also volunteered at a local animal shelter. I fed the animals and played with them. I felt happy to help. 

I can’t wait to hear about your summer!

Best,

Vân

Gọi số học sinh lớp \(7 B\) là \(x\) \(\left(\right. x \in \mathbb{N}^{*} \left.\right)\) (học sinh)

Số học sinh ban đầu lớp \(7 A\) là \(\frac{4}{5} x\) (học sinh)

Theo đề bài, ta có: 

 \(\frac{4}{5} x - 8 = \frac{1}{2} \left(\right. x + 8 \left.\right)\)

 \(\frac{4}{5} x - 8 = \frac{1}{2} x + 4\)

\(\frac{3}{10} x = 12\)

\(x = 40\) (thỏa mãn)

Vậy số học sinh là \(7 B\) là \(40\) học sinh

Số học sinh lớp \(7 A\) là: \(40. \frac{4}{5} = 32\) (học sinh)

Tổng số học sinh lớp \(7 A\) và lớp \(7 B\) của một trường là: \(40 + 32 = 72\) (học sinh)

⚡Vì \(M N / / B C\) nên \(\hat{A C B} = \hat{A N M} = 4 0^{\circ}\) và \(\hat{A B C} = \hat{A M N} = 5 0^{\circ}\)

⚡Vì \(C D\) là phân giác góc \(A C B\) nên \(\hat{D C B} = 4 0^{\circ} : 2 = 2 0^{\circ}\)

⚡Vì \(B D\) là phân giác góc \(A B C\) nên \(\hat{D B C} = 5 0^{\circ} : 2 = 2 5^{\circ}\)

Vậy \(\hat{D C B} < \hat{D B C}\)

Góc \(A O D\) và \(B O C\) đối đỉnh, góc \(A O B\) và \(C O D\) đối đỉnh

Diện tích mảnh vườn hình chữ nhật là: \(5.4 = 20\) (m²)

Diện tích mảnh đất trồng hoa là: \(20 - 11 = 9\) (m²)

Cạnh của mảnh đất trồng hoa hình vuông là: \(\sqrt{9} = 3\) (m)