bu busy with /on sth

be busy with sth.spend on sth.be busy doing sth.spend doing be busy with sth be busy doing sth/with sth be busy with sth 与be busy doing sth be busy doing sth和be busy with sth be busy with sth.be busy doing sth. get on with sth be busy with sth.什么意思 be busy with sth.的应用 be busy with sth的中文 有没有be busy with doing sth? be busy with sth 和 be busy dong