Tom had been studying French hard for nearly three years he mastered it．
#30569
A
after
B
when
C
since
D
before
推荐题目
Mrs．Black had such a wonderful time she visited her friend in London last year
#31303
A
when
B
that
C
which
D
as
Cloning plants is straightforward cloning animals is very complicated .
#34234
A
so that
B
although
C
while
D
as if
I was so familiar with her that I recognized her voice ________ I pickedup the phone.
#31811
A
the moment
B
after
C
before
D
while
________ I regret most is that I have promised to make friends with the dishonest girl.
#30318
A
How
B
What
C
Where
D
That