be essential to

对…不可缺少

be considerate of, be considerate of..., be content with, be contrary to, be convinced that, be covered with, be crazy about, be deep in thought, be deserving of, be detached from, be different from, be disagreeable to, be disgusted with, be doubled up, be due, be due to, be eager for sth., be eager to, be envious of, be equal to, be exposed to, be faced with, be familiar to, be familiar with, be far from, be favourable to, be fed up, be fed up (with ), be fed up with, be filled with, be fit for, be fond of, be free from, be friends with, be full of, be generous in, be generous with, be glued to, be good at, be good to,