be interested at后加什么

　　That is how I first came to be interested in the behaviour of prices.

　　這就是我首次對股票價格的變化產(chǎn)生興趣的原因。

　　They were always changing. It was all I had to be interested in the changes.

　　它們總是在不斷的變化著，這種變化才是我真正感興趣的東西。