alternatev.交替；轮流adj.间隔的；轮流的；交替的n.代替者；供替代的选择alternate host转换宿主,中间宿主,转主寄生alternate form更替卷,复本alternate type交替型alternate flow交替水流alternate hand交换手拍球alternate yarn交替线alternate fuel人造石油alternate unit备件, 替换部件alternate road预备路alternate leaf互生叶