Exactly______ the potato was introduced into Europe is uncertain, but it was probably around 1565.
#30010
A
whether
B
why
C
when
D
how
推荐题目
The reason _______ he was late was ________he hardly knew the way to the meeting place.
#33976
A
what; because
B
for which; that
C
that; because of
D
why; because of
 ________ it is, the boy never seems to be able to finish it off.
#30273
A
However interesting a book
B
Whatever interesting a book
C
How interesting a book
D
What an interesting book
____I had done it , I knew I had made a mistake.
#31622
A
Direct
B
A moment
C
Directly
D
Since