Qian Xuesen tried many times _________ he found the solution to the puzzle about space technology.
#31596
A
after
B
before
C
since
D
when
推荐题目
__________ is responsible for the Chenzhou train collision will be punished.
#34133
A
Whatever
B
No matter what
C
Whoever
D
No matter who
Mary believed it was just the license number that she had chosen ___brought her the good luck.
#34117
A
that
B
which
C
when
D
where
In some places women are expected to earn money men work at home and raise their children.
#80200
A
because
B
but
C
though
D
while
