1.What would happen if water pollution stopped?

2.Would we be happy if air pollution in the world were a better place?

3.If there were no pollution,would the world be a better place?

4.If I were you,I would take these bottles to the bottle bank.

5. If people didn't really care about the environment, they wouldn't try to save it.

6.The river wouldn't be so polluted if the factories didn't dump the waste into it.

7.We would be less worried if oil spills didn't have such destructive effects.

8.If we destroy the ozone layer, what would save us from the UV rays?

Một vật có khối lượng m = 4,5 kg buộc vào một sợi dây.

a.Chỉ ra các lực tác dụng lên vật? Đặc điểm của các lực này?

b. Biểu diễn trên hình vẽ các lực trên?( tỉ xích tùy chọn)