16.I doubt _______ they can complete the bridge ahead of time.
A. whether
B. that
C. why
D. what
17.The question he asked was _______ I come here.
A. that
B. how
C. what
D. because
18.Too many people are indifferent _______ others‘ troubles.
A. with
B. to
C. of
D. about
19.Let us see how dictionaries are made and how the editors _______ definitions.
A. lead to
B. arrive at
C. reach for
D. approach to
20.Shanghai is the place _______ I was born.
A. on which
B. in which
C. when
D. that
