问题补充：
—How many birds can you see in the trees?
—I can see birds in them.
A. hundreds of
B. five hundreds
C. hundred of
D. five hundreds of
答案：
(答案→)A. hundreds of
B. five hundreds
C. hundred of
D. five hundreds of
解析：句意：你能在树上看见多少只鸟？我能看见数百只鸟。数词中表示不确定的数字时，数词后加s,加of, hundreds of表示数百只，故选A
