你想知道高伟的弟弟多大了,你应该怎么问呢?________A.Who's that boy?B.How is your brother?C.How old is your brother?
( ) The doctor often tells him __________ more exercise.
( ) You should ___________ your little brother when your mother is out.
( ) Sometimes walking is __________ than driving during the busy traffic time.
( ) My sister was born _____________ a Friday morning.
( ) Mary is a student of___________.