(单选题)

—How old is your son?
—. We want to have a special party for his birthday.

A.Nine; nine

B.Nine; ninth

C.Ninth; ninth

D.Ninth; nine

参考答案：B

参考解析：

考查数词。句意：“你儿子几岁了？”“九岁了。我们想为他的九岁生日开一个特别的派对。”基数词意思是“几”，表示数量；序数词意思是“第几”，表示顺序。本题中，前空意思是“九岁”，表示数量，用基数词nine。后空表示的是他的“第九个生日”，表示顺序，用序数词ninth。故选B。

知识点：

—How old is your son?—______. We want to have a special party for his ______ birthday.