Question

His mother is ______. Today is his mother’s thirtiethbirthday.
A. thirteen         B. thirty          C. Thirtieth

Answer 1

B

解析试题分析：句意：他的妈妈三十岁了。今天是他妈妈的三十岁生日。根据后面的Today is his mother’s thirtieth birthday.可知应该是他妈妈三十岁了；故选B。
考点：考查数词的用法。