西宁哪里买冷冻牦牛肉:A great many of什么意思？？有这个词组吗？

A great many of什么意思？？有这个词组吗？ a good many, a plenty of, a varienty of,a great deal之间有什么区别? a great many, a great deal, a great amount of, a large part of的区别 great!in favour of you!什么意思 不懂这一句“in one part of the town a great many buildings were destroyed." a good many 等于a great many 是否相同? a ... of 什么意思? a part of 和great part of many and a lot of a great many为什么有个a呢？