What were Helen and Sally doing when it began to rain heavily？
Helen was sleeping _______Sally was reading a magazine．（ ）
A．whileB．untilC．beforeD．after
Mum，_____ I go out to watch a movie？
Yes，you can．But you must finish your homework first．（ ）
A．mustB．needC．willD．may
We finished the rest of the dinner ______ silence after we heard what he told us．（ ）
A．onB．atC．inD．of
Eric is not going to Nanjing by ______ plane．Instead，he is taking ______ train．（ ）
A．/， aB．a， /C．a， theD．the， a
I wonder _____in Guangzhou in two hours．
Of course．The high speed train is very fast．（ ）
A．when I can arriveB．when can I arrive
C．whether I can arriveD．whether can I arrive