________scores of times, but Derek still couldn’t understand how to use past participle in a concrete situation.
#32441
A
Having explained
B
Having been explained
C
Though it was explained
D
It was explained
推荐题目
Nowadays teens prefer going to the cybercafé ，_____ ,as is known to us, they can chat with their friends by QQ or play games.
#34380
A
which
B
where
C
that
D
when
it is normal for parrots to talk, Einstein, a small bird, is unusual in that whenever she hears a new word or sound, she repeats it over and over until she masters it.
#30576
A
As
B
When
C
While
D
Since
_____ China’s reform and opening up in late 1978, its quick development has aroused worldwide attention, which has made America anxious about it.
#80634
A
When
B
As
C
While
D
Since
The other day ,my father drove his car at _____I thought was a dangerous speed.
#32075
A
as
B
that
C
what
D
which