________ I have to give a speech, I get extremely nervous before I start.
A. Whatever B. Whenever
C. Whoever D. However
________ small, the company has about 1，000 buyers in over 30 countries.
A. As B. If
C．Although D．Once
He is so busy. He cannot afford enough time with his son ________ he wants to.
A．even if B．as if
C．because D．before
________ we have enough evidence, we can't win the case.
A．Once B．As long as
C．Unless D．Since
I have heard a lot of good things about you I came back from abroad.
A. since B. until
C. before D. When
Don't turn off the computer before closing all programs, ________ you could have problems.
A. or B. and
C. but D. so
