题目内容：

4.____________on time,this medicine will be quite effective.
A.taking
B.Being taken
C.Taken
D.Having taking
2.Who did the teacher _____an article for the wall newspaper?
A.has write
B.has written
C.have write
D.have written
3.__________the big snake,the little girl stood under the tree_______out of he life.
A.Saw,frightened
B.Seen,frightened
C>Seeing,frightened
D.To see,frightened