how old is he?复数是什么

how old is he?复数是什么 How old is he/she? (How old is he/she? How old is he?=同义句是什么? how old is he?的同义句 How'old-is·-He/she? How old is he的同义句 How old is he 改为同义句 How old is he?改为同义句 写同义句:How old is he? How old is he (同义句转换) how old is she/he?怎么回答?