Life is unpredictable, like a boundless sea. Sometimes calm, sometimes waves lapping. Therefore, human life will encounter many setbacks.

人生变幻莫测，如同无边无际的大海。时而风平浪静，时而巨浪拍岸。因此，人的一生就会遇到很多的挫折。

youdao

Sometimes the birds sat down on the sea in groups, near brown seaweed that rolled on the waves.

VOA: special.2010.03.06

All right. So, let's look at this in another way, sometimes it's hard to picture these waves combining.

好的，让我们从另外一个方面来看，有时候很难想象这些波函数的组合。

麻省理工公开课 - 化学原理课程节选

Sometimes you know, people, they come in big waves.

有时候，人们成群结队地来到这里。

上西区的富人 - SpeakingMax英语口语达人

Sometimes, the waves hit in succession -- often the highest not being the first, CNN meteorologist Ivan Cabrera said.

CNN: Widespread destruction from Japan earthquake, tsunamis

Pain can sometimes come in waves with nausea and vomiting.

CNN: What can I do for kidney stones?

Also, since radio waves sometimes arrive at your device not directly from the radio tower but rather by being bounced off a building or hill, these signals may be much lower in signal strength than if you had a clear line of sight view to the cell site.

FORBES: The iPhone 4 Antenna Unravelled