I had too much work to do last night . I didn t go to bed 11 o clock .A. in B.until C.

问题补充：

I had too much work to do last night . I didn t go to bed 11 o clock .

A. in B.until C. for.

答案：

解析：in 指的是在……内部。not … until 意思是：“直到……才”，until后跟表示时间的名词时，until是介词，“直到……为止”，for “为了”，故B 。