问题补充：
an hour in the morning and you will be looking for it during the rest of the day.
A. Losing
B. To lose
C. Lose
D. Lost
答案：
A. Losing
B. To lose
(答案→)C. Lose
D. Lost
解析：考查固定句型。祈使句+连词+陈述句=条件句，主句。本句=If you lose an hour in the morning, you will be looking for it during the rest of the day.
