—Can you watch TV school nights?
—Yes, but I have to be bed ten o’clock.
A. in; on; by
B. on; on; in
C. on, in; by
D. in; in; at
网友回答
A. in; on; by
B. on; on; in
(答案→)C. on, in; by
D. in; in; at
解析：此题重点考查介词的固定用法。On school nights；in bed；at ten o’clock。