a large number of、a lot of、plenty of、a great many有什么区别?

记住这些在使用时就不会混淆了.例句：\x0d1、A large number of high-tec products have(has) been made in that factory(那个工厂生产了许多高科技产品）a number of做主语时,动词可用单数,也可用复数.\x0d2、Don't hurry. We still have plenty of time.\x0dThere are plenty of such persons in our school.可数和不可数都可以.\x0d3、He got a lot of(lots of)homework(things)to do after school.可数和不可数都可以.\x0d4、They raised a great many(a good many)proposals at the meeting.只能是可数的.\x0d此外,表示大量,许多的还有a large quantity of,修饰可数和不可数名词,如：\x0dAs a result of destroying the forests, a large quantity of desert has coverd the land(毁林导致了大量土地的荒漠化）. On that day she received a large quantity of flowers.