---Mr. White didn’t come last night, did he? ---No. We for him. A whole night was wasted.A. had waited B. have been waiting C. were waiting D, had been waiting
____, he does not know the answer.
We were ____ to go out for a camp ____ it began to rain.
____ several times, the young scientist still kept on doing his experiments.
It was last October ____ they finally came back to their hometown.
My pen is missing. I can’t find ____ anywhere.