Stephen Hawking has expressed his opinion ___ humans might one day be able to make spaceships capable of such speeds that time on board would slow down．
#69972
A
that
B
whom
C
which
D
what
推荐题目
It was not until dark _____ he found _____ he thought was the correct way to solve the problem．
#68092
A
when; that
B
that; that
C
when; what
D
that; what
The professor could hardly find sufficient grounds _____his arguments in favor of the new theory.
#73299
A
to be based on
B
to base on
C
which to base on
D
on which to base
Clean water and fresh air are essential for our daily life, _______ we can’t live.
#66990
A
by which
B
without which
C
that
D
on which