It’s necessary for human beings to breath _______ and plants can produce it.
#17259
A
CO2
B
H2
C
O2
D
N2
推荐题目
—What       the weather       today?—It’s cold.
#17230
A
it; /
B
is; like
C
does; like
D
can; be
It’s nice _______ you _______ me with my lessons. 
#16757
A
for, helping
B
for, to help
C
of, to help
D
of, helping
—Your new sweater looks very beautiful, it fits you very well.—__________.
#17243
A
I’m glad to hear that
B
Thank you
C
No, no, yours is better
D
You are right
—Where have you been these days?—I have been to Bei Daihe with a friend      . 
#17283
A
in Chinese
B
of Japan
C
of American’s
D
from Canada