1. What fun it is to walk alone with full moon hanging in the sky.
A. /; a B. a; / C. the; / D. a ;the
2. The computer system _______suddenly while he was searching for information on the Internet.
A. broke out B. broke up C. broke in D. broke down
3. Parents should see to it _______ their children form the habit of brushing their teeth every day.
A. this B. that C. whether D. if
