________you’ve experienced it，you can’t understand how I felt.
#30226
A
Once
B
Because
C
Unless
D
While
推荐题目
I was walking along the road _____ someone patted me on the shoulder from behind.
#30746
A
while
B
immediately
C
when
D
the moment
The golden rule is not to waste time waiting for opportunity. Begin, ______ opportunity will find you.
#31329
A
and
B
when
C
so
D
because
The little boy won’t go to sleep_______his mother tells him a story.
#31821
A
or
B
unless
C
but
D
whether
________we went to visit Professor Smith, he________his research work.
#31550
A
The first time; devoted to
B
Whenever; was concentrate on
C
For the first time; was busy with
D
Each time; was absorbed in