— _____ is she?
— She's five.
How old…? 是对年龄进行提问的特殊疑问句，答语常用：主语+be+基数词+year(s)/ month(s) old 或直接说出年龄。
— ______ is your birthday?
— It's on July 9th.
when引导的特殊疑问句是对时间的询问，回答时常用介词in,on,at等构成表示时间的介词短语。根据答语可选B。
— It's my birthday today!
— _____
Happy birthday (to you) ! 是祝贺别人生日的一句常用祝福语。