Choose the correct answer.

The scientists will explain some techniques on how to _______ household things.

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

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

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

Mary: _____________.

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

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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).