a lot of的同义词:
a great deal n.大量
a mass of adj.大量的
large numbers of 大量的, 数目很多的
large numbers of 大量的, 数目很多的
plenty of adj.许多
a number of adj.许多的
lots of 许多
a good many adj.很多
a great many adj.很多
表示许多的词有很多，区别在于：
1。只接可数名词
many , many a (后接单数可数名词)
a good(great) many, a (good, large, great) number of
2。只接不可数名词
a (great ) large amount of , large amounts of
a (good, great ) deal of
3。即可接可数名词又可接不可数名词
a lot of, lots of , plenty of
a (large) quantity of , (large) quantities of
注意：quantity , plenty构成的短语多接不可数名词