－Areyousureyouhaveto?It’sbeenverylate.  －Idon’tknow

问题详情：

－Are you sure you have to? It’s been very late.

   －I don’t know _______ I can do it if not now.

    A. where        B. why           C. when         D. how

【回答】

C

知识点：相似 相近词比较

题型：选择题