1. They lost their way in the forest, and _______ made matters worse was that night began to fall.
A. it B. which
C. that D. what
2. Patience is a kind of quality — and that is ___A___ it takes to do anything well.
A. what B. which
C. which D. how
3. It has come to my notice _______ some of you have missed classes.
A. what B. which
C. that D. when
4. “What were you trying to prove to the police?” “___ I was last night.”
A. That B. When
C. Where D. What