undergo,experience,sustain,suffer这些动词均有“经历，经受，遭受”之意。undergo〓多指经受艰难、痛苦、不愉快或危险等事。experience〓指亲身经受或体验某事。sustain〓指遭受痛苦或承受负担。suffer常可与sustain通用，尤指受到损害或伤害。underground,subway,tube这些名词均可表示“地铁”之意。underground〓一……