idea是可数名词。
idea
n.想法;构思;主意;印象;概念;意见;看法;信念;
复数: ideas;
例句:
It seemed like a good idea at the time.
当时这主意好像不错。
It would be a good idea to call before we leave.
我们出发之前打个电话是个好主意。
I'd like to take this idea a step further.
我想把这一思想深化一步。
I had some idea of what the job would be like.
我对于这份工作有了一些了解。
By that time I had lost interest in the idea.
那时我已经对此想法失去兴趣了。