a great number of修饰可数还是不可数

　　A great number of people came to the meeting from all over the country.

　　来自全国各地的许多人参加了会议。

　　His errors spawned a great number of economic loss.

　　他的错误造成了极大的经济损失。

　　A great number of problems have arisen.

　　出现了许多问题。