-----I called you at about half past eight last night but nobody answered. -----Oh, I _____ in my office at that time.
It is recognized that the part ___ the UN plays in international relations is important.
Who would you rather ______ with the teacher about the problem?
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.