1.It/eating
2.wants
3.Have studied
4.more and more interesting
5.Our/theirs
6.was watching
7.is going to leave
8.have rained
9.going
10.to close
11.have been waiting
12.not to play
13.cleans/because
14.had learned
15.is going to look
16.Do not talk
17.met
18.clever
19.well/better
20.carefully.