Ⅰ. 单项选择(每小题2分，共20分)
1. My sister entered ________ university after graduating from high school.
A. a B. an C. /
2. Please check your paper to ________ there are no mistakes.
A. think of B. try out
C. find out D. make sure
3. ________ the beginning of the year, we hope that we are going to have a happy life.
A. In B. On
C. At D. For
