be cautious of

留心…，谨防…

be attentive to, be available for, be available to, be aware of, be beneficial to, be better off, be blessed with, be blind to, be bound for, be bound to, be bound to do, be bound up in, be bound up with, be burned to a crisp, be busy doing, be busy with, be capable of, be careful of, be careful with, be caught up in, be centered on, be central to, be certain of, be certain to do sth, be characteristic of, be charitable to, be civil to, be clear about, be close to, be committed to doing sth., be comparable to, be comparable with, be composed of, be concerned about, be concerned with, be confronted with, be connected to, be conscious of, be considerate of, be considerate of...,