Choose the correct answer.

We should take a bus often _______ we can help reduce air pollution in the city.

Choose the correct answer.

If I have time, I _______ some trees in my neighborhood.

Choose the correct answer.

A lot of people _______ trash into rivers and make the water polluted.

Choose the correct answer.

Jane: What about putting more trash cans on the streets?

Mary: _____________.

Choose the correct answer.

Burning coal to produce electricity _______ the air.

Find the mistake.

Governments worldwide (A) are working (B) together to protect (C) the environment for (D) pollution.

Find the mistake.

If you don’t pay (A) attention, you will (B) understand (C) the lesson (D).