I.
1.to>for
2.should>shouldn't
3.don't>doesn't
4.a>an
5.has>have
6.feels>feel
7.shouldn't>should
8.eated>ate
9.speaks>speak
10.are>is
11.did go>went
12.an>a
13.bad>good
14.doesn't>don't
II.
1.b
2.c
3.a
4.c
5.d
6.b
7.a
8.c
9.a
10.b
11.a
12.c
13.b
14.a
15.c
16.c
17.c
18.a
19.d
20.c
III.
1.six
2.because they much study too much everyday, and don't have enough time to take a rest
3.students should play sports after school to relax
4.because it's necessary to development of their brain
5.Yes,it is
