an amount of,a number of和a quantity of之间的用法有何不同

an amount of,a number of和a quantity of之间的用法有何不同 a number of an amount of a quantity of区别 请问quantity of,number of,amount of的用法 a number of和an amount of的区别? a amount of 和the amount of的用法是否和a number of 和the number of 的 a amount of 与the amount of 的用法,它们与the number of和a number of的 an amount of,a number of,the amount of,the number of的意思与区别? a quantity of和a number of的区别 a quantity of ,many of ,masses of ,the number of 的意思及用法 an amount of 和 a large number of 的区别是什么? a large number of 和a large quantity of a number of VS a quantity of 懂的请进