be occupied in

忙于…，正从事…

be involved in, be irrelevant to, be jealous of, be keen about, be keen on, be known as, be known for, be known to, be likely to, be located in, be lost on, be loyal to, be made of, be made up of, be made up of..., be married to sb., be native to, be no match for, be noted as, be noted for, be off one's head, be on a diet, be on firm ground, be on hands and knees, be on one's mind, be on the advance, be on the drink, be opposed to, be out for, be out of employment, be out of one's mind, be out of step, be out of style, be pleased with, be popular with, be prejudiced against..., be qualified to, be related to, be relevant to, be reluctant to,