—Can you watch TV school nights?—Yes but I have to be bed ten o’clock.A. in; on; byB.

问题补充：

—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

答案：

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。