The new buyer identified a dozen new sources for the material, ___________ proved to be reliable.
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.
___ Mr. Smith is waiting to see you. He appears to be quite____ important person.