Question

【題目】He sometimes asked himself the question ______ his research was worth devoting his life to.

A．that B．if C．whether D．how

Answer 1

【答案】C

【解析】句意：他有時候問自己這個問題——他的研究是否值得將他的畢生都投入進去。根據句意，可見是表示懷疑，所以要選表“是否”的詞；而空缺處引導同位語從句，______ his research was worth devoting his life to作the question的同位語，if不能引導同位語從句，故選C項。