The group of doctors has spent 8 months _____ the side – effects of this new vaccine.

I don’t have any money, so I can not buy that book.

If people really cared about environment, they _____ waste into rivers.

This is the first time they have seen this film.

Rewrite each sentence so that it has the same meaning as the first one.

We are going to organize a campaign to raise people’s awareness of environmet protection.

→ A campaign …………………………………………………………………………….

Combine two sentences into a new one, using the words in brackets. Do not change the given words in any way.

 He walked slowly. His leg was painful. (BECAUSE OF)

They have caused serious water (23) _____ by dumping industrial waste into the lake.