be keen about

喜爱，对…着迷

be in (good) shape, be in charge of, be in despair, be in drink, be in fashion, be in for, be in honour of sb.(sth.), be in love with, be in one's hands, be in sb.'s (sth.'s) honour, be in sympathy with, be in the habit of, be in the wrong, be incapable of, be inferior to, be innocent of..., be interested in, be involved in, be irrelevant to, be jealous of, 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 occupied in, be off one's head, be on a diet, be on firm ground,