他一直在进行一些反常的性活动。

He had been engaging in some kind of kinky sexual activity.

《柯林斯英汉双解大词典》

大多数人认为学生应该少花时间记忆事实，给创造性活动更多的空间。

Most said students should spend less time memorizing facts and have more space for creative activities.

youdao

在实验室的挑战性活动（比如驾车）的模拟中，那些觉得生活在自己的掌控之中的人产生的应激激素（比如皮质醇）更少。

In laboratory simulations of challenging activities such as driving, those who felt in control of their lives pumped out lower levels of stress hormones such as cortisol.

youdao

This almost certainly is not the right story but again, just as in phobias, some ideas of classical conditioning may play some role in determining what we like and what we don't like sexually.

这个解释肯定是错的,但是，与在恐惧症中的作用相同，经典条件作用,或许对我们在性活动方面的喜恶,起着一定的决定作用。

耶鲁公开课 - 心理学导论课程节选