她拒绝在一双鞋上花费超过20英镑。

She refuses to spend more than £20 ___on a pair of shoes.

我已经在这上面浪费了太多时间。

I've wasted too much time ___on this already.

我爱它，我把我所有的时间都花在它上面。

I love it and I spend all my time ___on it.