be very useful at

精通

be surprised at, be suspicious of sb., be suspicious of sth., be taken with sb/sth, be tempted to do, be thick with, be tired of, be to blame, be to blame for, be to do sth., be tolerant of, be true of, be true with, be typical of, be unable to, be unaware of, be up against, be up to, be used to, be useful to, be willing to, be witness to, be worth doing, be-, beach, beach buggy, beach-ball, beach-head, beachcomber, beachwear, beacon, bead, beadle, beady, beagle, beagling, beak, beaked, beaker, beam,