“ On no account” the teacher said “ open in day and night. ”A. the door to the basemen

问题补充：

“ On no account” , the teacher said, “ open in day and night. ”

A. the door to the basement is to be left

B. the door to the basement was to be left

C. is the door to the basement to be left

D. was the door to the basement to be left

答案：

A. the door to the basement is to be left

B. the door to the basement was to be left

(答案→)C. is the door to the basement to be left

D. was the door to the basement to be left

解析：句意：--老师说：地下室的门绝不能日日夜夜开着。On no account“绝不”，如果放在句首的时候，谓语用部分倒装，be动词/情态动词/助动词放在主语前面，所以选C。