Ⅰ.用所给词的适当形式填空
1．It ________ (snow)when he arrived at the station.
2．As I was coming here，I ________ (meet) your brother.
3．Great changes ________ (take) place in Beijing since it was liberated.
4．I ________ (tell) you as soon as I know.
5．We’ll wait until the doctor ________ (come)．
6．The telephone rang when I ________ (take) a bath.
7．As he talked on，he ________ (get) more and more excited.
8．They talked as they ________ (walk) along the river.
9．He was punished only because he ________ (break)the law.
10．As he was in a hurry，he ________ (leave)his bag at home.
