a good many,a plenty of,a varienty of,a great deal之間有什麼區別?

題目：

a good many,a plenty of,a varienty of,a great deal之間有什麼區別?

解答：

a good many 只修飾可數名詞
plenty of 可數不可數都行
a variety of 修飾不可數名詞
a great deal of修飾不可數名詞
不存在a great deal和 a plenty of,他們是錯誤的短語.