The computer system __________ suddenly while he was searching for information on the Internet.
I don’t think it is teachers who ______ for giving students too much pressure.
Readers can ______quite well without knowing the exact meaning of each word.
______ it is to have a picnic in the hills on such a nice day!
You must apologize ______ her ______ what you have done.
The bad weather discouraged us ______ on the picnic and we had to stay at home.