The rivers will become dirtier and dirtier _______ we take action to protect them.
#55533
A
since
B
if
C
until
D
Unless
推荐题目
______I know him, ______I hardly talk to him.
#58081
A
Although; but
B
Although; /
C
/; Although
D
But; although
—_______he is very old, he works very hard. — Wow, great. I should learn from him.
#56197
A
Although
B
However
C
Because
D
So
—Mom, can I watch TV?—Yes, but you must do your homework _________ you can watch it.
#55399
A
before
B
after
C
because
D
or