Are these ____ the twins'?---Yes,they are.A.key B.box C.keys D.boxs
问题描述：
Are these ____ the twins'?---Yes,they are.A.key B.box C.keys D.boxs
答
答案选C
因为：A、B都是单数不考虑了。D选项拼写错误，应该是boxes.
答
C.keys
答
C
首先 are 所以要复数
但box的复数是boxes错
所以选keys