be busy( )sth

如题所述

第1个回答  2020-03-28
1)be
busy
doing
sth.
忙于做某事,动词用成v.ing
They
are
busy
doing
their
homework.
他们正忙于做作业。
2)be
busy
with
sth.
忙于做某事,with后跟名词或代词
They
are
busy
with
their
homework.
他们正忙于做作业。
相似回答