问题
选择题
---Are Mr. and Mrs. Wang living alone in the house?
---Yes, they have three sons, but ______ of them live in their own houses.
A．neither ????
B．both
C．all
D．none
答案
答案：D
根据but可知下文为否定的意思，neither表示两个都不，哦、none表示三个及三个以上都不，none指代三个儿子，选D。