You become so deeply absorbed in an activity that you lose track of time.

你是那么专注于一项活动，以致忘了时间。

《柯林斯英汉双解大词典》

youdao

youdao

Other scientists have shown that sun spot activity can be measured in periods of time that last about eleven years.

VOA: special.2009.09.29

To some extent, if we put you in an fMRI scanner and observed what you're doing in real time, by looking at the activity patterns in your brain we can tell whether you are thinking about music or thinking about sex.

某种程度来讲,如果我们对你进行,功能性核磁共振成像扫描,观察你的实时活动,通过观察你的大脑活动模式,我们可以看出你是想到了音乐,还是想到了性

耶鲁公开课 - 心理学导论课程节选

Volcanic activity broke the large island into pieces that came to the surface of the sea over time.

VOA: special.2009.12.16

They can also send the information wirelessly to iPhone apps that graph your activity over time.

WSJ: Keeping Fit, One Step at a Time

They may also begin to need to do more and more of the activity over time to feel the effects, and experience physical and psychological withdrawal symptoms if they can't do it.

BBC: Why anything can be addictive

New software goes beyond passive recording to alerting law enforcement about suspicious activity in real time.

WSJ: Crovitz: In Praise of Surveillance Cameras