选出能替换句子中画线部分的选项。
1 ．All of the students have studied very hard ．
A ．have worked
B ．has worked
C ．have learned
D ．has done
2 ．We have learned a lot of things in the country ．
A ．a lot
B.lots of
C ．a great number of
D.a number of
3 ．What do you go there for?
A ．How
B. Why
C ．Whose
D. When
4 ．I'm never late for school ．
A ．early
B ．always early
C ．much better
D ．much fine
5 ．I do well in mathematics.
A ．am good in
B ．am good at
C ．do best
D ．do my best
