1．If you want to do the experiment again，you’d better be more careful ________ you made a mistake.
A．when B．why C．where D．that
答案 C [你最好在你犯过错的“地方”更小心点，故选where，where引导状语从句。]
2．Jessica was a newcomer to our class，but，________ we didn’t know her，she was warmly received.
A．as B．since C．for D．although
答案 D [although引导让步状语从句。]