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Pollution is one of the biggest problems in the world today. In many places, rubbish is thrown into lakes and rivers.
In some cities, the air is filled with pollution.
If we do not act to improve the environment, more living things will be killed by pollution.
We should separate rubbish into different groups. In this way, it can be recycled and reused. We had better plant more trees.
If we can do these, we will make the world a better place to live in.
| A．This makes some old people and children ill. |
| B．As well as people, animals are also harmed by pollution. |
| C．We can make our lakes and rivers cleaner and cleaner. |
| D．It’s time for all of us to take action right away! |
| E．Because of this, these places have already been polluted. |
| F．Trees reduce dust and help keep the air clean. |
| G．A few of us should take action to protect the environment. |
同类型试题
y = sin x， x∈R， y∈[–1，1]，周期为2π，函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x， x∈[–1，1]， y∈[–π/2，π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
y = sin x， x∈R， y∈[–1，1]，周期为2π，函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x， x∈[–1，1]， y∈[–π/2，π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
