用括号中所给单词的适当形式填空。
I think there will be          (few) books in the future because people will read on          computers.
We had a            ( discuss) about our hobbies in the class meeting.
The water            ( pollute ) is very serious in our country.
It’s            ( possible ) to learn English well if we don’t study hard.
Many            ( travel ) come to China every year.