----_____is it that is troubling Mary ?----Working out the maths problem..
#70665
A
What
B
How
C
Why
D
Which
推荐题目
（湖南省怀化市2014年高三第二次模拟考试）30. , and you will realize your dream of being successful.
#66656
A
Making great efforts
B
To make your efforts
C
A bit more effort
D
If you double your efforts
Some scientists have questioned the theory ______ CO2 is causing dangerous global warming.
#68429
A
which
B
what
C
that
D
why
_______ is agreed that the traffic accident was largely ________ the driver’s carelessness.
#68023
A
He, leading to
B
It, resulted in
C
It, due to
D
He, thanks to
Have you noticed the problem ___ he is now in low spirit ? ____ come?
#73919
A
where, What
B
that, How
C
in which, For
D
what, As