问题
选择题
We must never think that we are good at everything __________ others are good at nothing.
A．since
B．however
C．while
D．as
答案
答案：C
题目分析：考查引导词，since意思“自从”，however意思“然而”，表示转折；while意思“当…时候”，谓语动词是延续性动词，不用短暂性动词， as意思“当…时候”，侧重指主句和从句动作同时进行，所以选C
点评：引导词是常考内容，做引导词题时，首先知道引导词的意思，然后根据句子意思，选择正确的答案