The women danced in semicircles while the men played musical instruments.

男人们演奏乐器时，妇女们围成半圆随音乐起舞。

Now, if you watch the news, the weather channel, for example, sometimes you'll see something like this, you'll see lines with semicircles moving.

如果你看新闻的话，比如说气象频道，有时你会看到这样的东西，你会看到带半圆的移动的线。