76.I doubt _______ they can complete the bridge ahead of time.
A. whether B. that C. why D. what
77.The question he asked was _______ I come here.
A. that B. how C. what D. because
78.Too many people are indifferent _______ others‘ troubles.
A. with B. to C. of D. about
79.Let us see how dictionaries are made and how the editors _______ definitions.
A. lead to B. arrive at C. reach for D. approach to
80.Shanghai is the place _______ I was born.
A. on which B. in which C. when D. that
76.正确答案：A答案解析：doubt 用在肯定句中，之后的宾语从句用 whether 或 if 引导。用在否定句中，后接宾语从句用 that 引导。