______yearafteryear,tigersarebeco

______ year after year , tigers are becoming fewer and fewer.A.Having been killedB.KillingC.KilledD.Having killed

参考答案：
C解析考察非谓语动词.一年又一年的捕杀,老虎变得越来越少.过去分词表示被动的,发生过的动作,其逻辑宾语为句子主语.故选C