be busy at /with sth ;busy doing sth 忙于某事
eg .She's busy with her preparation for tha party .
get busy着手干
eg.We'll have to get busy if we're going to be ready
in time.
be busy oneself with sth ;be busy onself doing sth 让自己忙于做某事
be strict with sb /sth 对某人或某事严格