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

VOA: special.2009.12.16

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

At the same time, the Norfolk Police Constabulary is investigating the possibility of criminal activity.

VOA: special.2010.04.27

December is a time of holiday gift-giving and strong business activity in many places.

VOA: special.2010.12.24

"We can say that 50 percent of the burden of obesitycan be contributed by having no leisure time physical activity."

VOA: standard.2010.08.10

The federal government is encouraging schools to make more time so children can participate in physical activity.

VOA: standard.2010.03.09

Others last for months or even years. There is no clear way of predicting at the present time how long this activity might go on for."

VOA: standard.2010.04.16