When someone gets old they often go to live in a home with other old people ________ there are nurses to look after them.     

He wrote a letter ________ he explained what had happened in the accident.

The first week of university is an exciting time _______ freshmen familiarize themselves with their college and make new friends.

Mr. Duncan raised an unnecessary question __________ he then failed to find an answer.

Some fans, _____ money was a big problem, could not afford to go to the concert to see their star play.

—How about your job-hunting?
—No luck. Now, I’ve reached the stage ______ I don’t care what I do.           

It is recognized that the part ___ the UN plays in international relations is important.

Gun control is a subject_______ Americans have argued for a long time.

I think I’m not the kind of person ________ likes to sharing everything with others.
A what            B which        C who          D when

We can never forget the days _______the two astronauts in spaceship worked together and the days _______we spent together.