He was sleeping ____ someone knocked on the door.
A. when B. while C. as D. after
You will fall behind others ______ you work hard.
A. while B. until C. unless D. when
When I got to Beijing, it began to rain ______.
A. heavy B. heavily C. easily D. hardly
While she _____, I was watching TV.
A. was cooking B. gets out of the room
C. comes to visit me D. is working
Li Na is famous all the tennis fans in China know her.
A. too; to B. enough; to
C. as; as D. so; that
What ____ you ____ at this time yesterday?
A. are; doing B. were; doing
C. did; do D. have; done
