In this experiment, they are woken up several times during the night, and asked to report what they _____.
When _____ the letter, tears came to her eyes.
Did he find _____ hard to learn a foreign language?
The computer system _____suddenly while Paul was searching for information on the Internet.
___ Mr. Smith is waiting to see you. He appears to be quite____ important person.
I will go to Beijing on business tomorrow, do you have anything ____ to your son studying in Peking University?