Trong 1 phút, người đó đi được:

\(\dfrac{350}{5}=70\left(m\right)\)

Trong 1 giờ, người đó đi được:    

\(70.60=4200\left(m\right)=4,2\left(km\right)\)

1. have you known

2. have you been doing

3. have Charles visited

4. have been watching 

5. has he studied

6. Have you been waiting

7. haven't seen

8. has he been waiting

Air pollution is a cause of ill-health in human beings. In a lot of countries there are laws limiting the amount of smoke which factories can produce. Although there isn’t enough information on the effects of smoke in the atmosphere, doctors have proved that air pollution causes lung diseases. The gases from the exhausts of cars have also increased air pollution in most cities. The lead in petrol produces a poisonous gas which often collects in busy streets surrounded by high buildings. Children who live in areas where there is a lot of lead in the atmosphere cannot think as quickly as other children and they are clumsy when they use their hands. There are other long-term effects of pollution. If the gases in the atmosphere continue to increase, the earth’s climate may become warmer. A lot of the ice near the Poles may melt and may cause serious floods.

1. What can make people sick?

➜Air pollution can.

2. Where does smoke come from?

➜It comes from factories.

3. Can air pollution cause lung diseases?

➜Yes, it can.

4. What else can cause air pollution in cities?

➜The gases from exhausts of cars also can.

5. Why does the earth’s climate become warmer?

➜Because the gases in the atmosphere continue to increase.

B. Thứ hai thế giới (sau Mĩ)

However Linda earns a low salary, she gives some money to her parents every month.

chocolate là danh từ không đếm được

Which word has different stress pattern?

A. Noisy

B. Ahead

C. Correct

D. Belong

Noisy có trọng âm rơi vào âm tiết thứ nhất

Những từ còn lại trọng âm rơi vào âm tiết thứ hai