1¡¢In much of the animal word, night is the time ________for sleep —— pure and simple.

  A. set aside      B. set down         C. set off          D. set up

2¡¢It was not until near the end of the letter  ___        she mentioned her own plan.

A.that              B.where             C.why               D.when

3¡¢It’s Sunday today. I’m glad I____________ go to school.
A.haven’t to
B.don’t have got to
C.haven’t got to
D.won’t have got to