根据句意，用所给词的适当形式填空。

What do you think about the air ________(pollute)in your hometown?

用所给单词的适当形式填空。

Someday you’ll find a foreign language a bridge to a lot of ________．(know)

用所给单词的适当形式填空。

They don’t know why you talked to them so ________．(angry)

用所给单词的适当形式填空。

It is a ________ for me to stay with you．(please)

用所给单词的适当形式填空。

Which river is the second ________ river in the world?(long)

用所给单词的适当形式填空。

After a day’s walk, she felt so tired that she couldn’t go ________．(far)

用所给单词的适当形式填空。

I think this dictionary is ________ for your study．(help)

用所给单词的适当形式填空。

The doctor’s ________ made all of them sad．(dead)

用所给单词的适当形式填空。

December is the ________ month of the year．(twelve)

用所给单词的适当形式填空。

How can you make yourself ________ if you cannot express yourself dearly．(understand)