【题目】It is known to us all that such deer mainly green grass.
A.feeds; with
B.feed; on
C.feed; with
D.feeds; on

【答案】B
【解析】feed on“以……为食”。deer的单数和复数形式一样，由such deer可知为复 数形式；句意：众所周知，这种鹿以青草为主食。根据句意，故选B。