什么时候用take什么时候用took？

这里用took．
一般过去时用took ．因为这句话的意思是：我花了5元买了那块橡皮，所以应该是过去的事．
一般现在时才用take．

此处用took
这一句的意思是"我花费5元买了那块橡皮",买橡皮的事实已成过去.所以用took是可以的.
如果用takes应该也是对的,因为It是单数.但用take是不行的,单复数问题.

题目是:买那块橡皮花了我五元.
从句意理解,已经买完了,所以用过去时, took.
现在时:It usually takes us half an hour to walk to school.走路去学校通常花费我半个小时.

took
took是take的过去式，是指过去的事。
It ---me 5 yuan to buy that eraser. 这应该是过去的事。
现在式：
I plan to take biochemistry this semester.
People in this locality used to take two meals a day.
The flight will take three hours.
They're going to take a train to the capital.
I take her to be honest.
I'll take five pounds of beef.
Take Mr. White. He never shouts at his wife.
I'm sure this opera will take.

我觉得应该是用took,
因为这一句的意思是"我花费5元买了那块橡皮",那么买了橡皮就是已经过去了的事,所以要用过去式.
took是take的过去式.