题目内容：

the students are busy with their homewark all the time(同义句）
millie is 12.(两种）
they really have fun at the party.
they are both good swimmers in the club

优质解答

1.The students are busy with their homework all the time.
=The students are busy (in) doing their homework all the time.
2.Millie is 12.
=Millie is 12 years old.
=Millie is at the age of 12.
3.They really have fun at the party.
=They really enjoy themselves at the party.
=They really have a good time at the party.
4.They are both good swimmers in the club.
=Both of them are good swimmers in the club.
=They are both good at swimming in the club.
=They both do well in swimming in the club.