---How old is your mother?-She is years old. Today is her birthday.A. fourteen；fortieth

问题补充：

---How old is your mother?

---She is years old. Today is her birthday.

A. fourteen；fortieth

B. fourty; forty

C. forty;fortieth

D. fortieth;forty

答案：

A. fourteen；fortieth

B. fourty; forty

(答案→)C. forty;fortieth

D. fortieth;forty

解析：句意：---你的妈妈多少岁？--她四十岁了，今天是她的四十岁的生日。第一空应该用基数词，故排除BD；第二空应该用序数词。故选C。

考点: 考查数词的用法。