【题目】-----Why are you just sitting here while they are rushing off their feet?
-----How can I help _______ they won’t let me?
A. though B. in case C. when D. as
在线课程【答案】C
【解析】
考查连词辨析。句意：——为什么你坐在这里，而他们却忙得不可开交 ?——既然他们不让我帮忙，我怎么能帮忙呢?when在此处是“既然”的意思，A. though尽管；B. in case万一；D. as因为。根据句意故选C.