—Mary，I don’t know ____ you can come tomorrow morning.—No problem! I’ll be here _____I’m free then.
#55784
A
if；if
B
if; whether
C
whether；till
D
whether；until
推荐题目
Tom didn’t give up studying ________________ he failed many times.
#57075
A
but
B
even though
C
because
D
if
—Which do you prefer, tea or coffee?—I don’t care. ______ is fine.
#58395
A
Either
B
Neither
C
Both
D
All
----May I go swimming this afternoon? ----I'm afraid not _______ you have finished your homework.
#55714
A
unless
B
because
C
if
D
though
The earth will become worse and worse ________ we do something to stop her from being polluted.
#55977
A
if
B
even if
C
when
D
unless