curiosity

只是出于好奇，你是怎么得到我的地址的？

Just out of ___curiosity, how did you get my address?

我的好奇心占了上风，我打开了信封。

My ___curiosity got the better of me and I opened the envelope.

她的好奇心占了上风；她必须看看盒子里面有什么。

Her ___curiosity got the better of her; she had to look inside the box.