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
Children’s brains can’t develop properly_______ they lack protein.
#79950
A
when
B
since
C
because
D
unless
They were still working in the fields __ it had got dark.
#79700
A
even if
B
as if
C
in so far as
D
so that
Liao Fan, a Chinese actor, finally got to know real success tastes like when he won the prize for Best Actor at the 64th Berlin film festival.
#30101
A
when
B
how
C
what
D
where
One advantage of owning your own car is you can go anywhere at any time you like．
#33141
A
when
B
why
C
what
D
that
Doris’ success lies in the fact _______she is co-operative and eager to learn from others.
#30184
A
which
B
that
C
when
D
why