§1.助动词和情态动词的定义..............
§2.can, may, must...............................
§3.Will you ~?和Shall I (we)~?..........
§4.would和should...............................
§5.have to..............................................
§1.助动词和情态动词的定义..............
§2.can, may, must...............................
§3.Will you ~?和Shall I (we)~?..........
§4.would和should...............................
§5.have to..............................................