The old man often_________ to the rodio in the morning三个选一个：A.listen B.listening C.listens
问题描述：
The old man often_________ to the rodio in the morning三个选一个：A.listen B.listening C.listens
答
c,选择一个动词,而B是ing形式不能单独动词,从A,C中选,the old man 是主语并且是单数所以动词要用加s