问题
单项选择题
A．Because more and more people move into big new houses.
B．Because many old people sell their house after their children leave.
C．Because people want to sell the old house to get money and build their own house.
D．Because children often ask their parents to sell the old house.
答案
参考答案：B
解析：[听力原文]Why is it easy for people to buy an old house