—_____do you have a class meeting?— Once a week.
#17026
A
How long
B
How often
C
How soon
D
When
推荐题目
It’s necessary for human beings to breath _______ and plants can produce it.
#17259
A
CO2
B
H2
C
O2
D
N2
—We can see the signin the public places. What does it mean?—It means________.
#17198
A
NO PHOTOS
B
NO FISHING
C
NO PARKING
D
NO SMOKING