Question

---How old is your grandpa this year , Tom ?
--- ___________. And we are planning a party for his ________ birthday.

A．ninety ; ninety	B．ninetieth ; ninetieth
C．ninety ; ninetieth	D．ninety ; ninetieth

Answer 1

C

解析试题分析：句意：汤姆，你的爷爷今年多大年纪了？九十。我们为他的九十岁生日正筹划晚会。ninety90岁，年龄用基数词；his ninetieth birthday他的九十岁生日，要用序数词。故选C。
考点：考查数词。