At that time I had no idea ________ I could hand it to him without being seen.A.if B.how C.which D.that how选B为什么不选D
问题描述：
At that time I had no idea ________ I could hand it to him without being seen.
A.if B.how C.which D.that how
选B为什么不选D
答
因为这是一个疑问句，并非陈述句
答
名词后面加idea一般表示同位语从句，用于解释idea的内容。
而此题的意思是当时我不知道自己该怎样把东西交给他。
故用how表示怎样，用that就会显得多余且意思误差。
答
have no idea= don't know （ 不知道 ）
其后可直接跟特殊疑问词引导的陈述句.
译文：那时,我不知道怎样才能偷偷地将东西交给他.