He is not ai school.I think he ___ be ill.下划线处填写什么答:may 情态动词有can (could), may (might), must, have to, shall (should, will (would), dare (dared), need (needed), ought to等. 情态动词无人称和数的变化;不能单独使用,必须与其后的动词原形构成谓语 一、 can, could 1) 表示能力(体力、知识、技能).Can you lift this heavy ...