4.____________on time,this medicine will be quite effective.A.takingB.Being takenC.TakenD.Having taking2.Who did the teacher _____an article for the wall newspaper?A.has writeB.has writtenC.have writeD.have written3.__________the big snake,the little girl stood under the tree_______out of he life.A.Saw,frightenedB.Seen,frightenedC>Seeing,frightenedD.To see,frightened

C C C

4C
2C
3C

4.C
Taken on time:"如果按时服用," 这是过去分词短语,因为与主语this medicine形成被动关系（药被服用）,所以选过去分词,表被动.
2.C
“老师让谁为墙报写了一篇文章?”
这句话是下面这句的提问形式：The teacher had whom write an article for the wallpaper.
3.C
"看到那条大蛇,小姑娘站在树下吓得魂飞魄散."
seeing the big snake 的逻辑主语是the little girl,因此用现在分词表示主动,而后面frightened out of her life 的逻辑主语仍然是the little girl,她是“被”吓得,所以用过去分词

c
A
c
第一题
If it is taken on time 省略前面的
第二题
原句是the teacher has sb write an aricle for the wall newspaper
考的是has sb do sth
第三题
独立主格加被动语态。