1 . 选词填空 while/as/when。
1. ________ she was listening to the radio, she fell asleep.
2. She sang ________ she went along.
3. It was raining hard ________ we arrived.
4. Things are getting better and better ________ time goes on.
5. He was watching TV ________ I was reading a book.
6. I was walking on the street ________ I came across a friend of mine.

2 . ________ he passed away in 1961, Mei Lanfang had been performing and encouraging the spread of Peking Opera for almost 60 years.

A．Once

B．As

C．Until

D．Since