Birds and animals eat insects,but all of them________together kill insects far fewer than spiders.A.have been put B.being put C.put D.to be put
问题描述：
Birds and animals eat insects,but all of them________together kill insects far fewer than spiders.
A.have been put B.being put C.put D.to be put
答
B
答
感觉是B
不确定
答
B
句中已经有动词 kill 所以不用A,C
to be put表将来,不合语境
用B