Boys tend to form play groups that are competitive in nature.

男孩倾向于形成具有竞争性质的游戏团体。

We should do play group on weekends more often.

我们周末应该多搞点团队活动。

It was unclear what precautions, if any, had been taken, or whether that group had played any role in the assaults.

目前尚不清楚他们采取了怎样的预防措施(如果真有采取的话)，也不清楚该组织是否真的参与到了袭击之中。

I'd let her take the children to play group, sometimes the park.

我让她带孩子玩游戏或者去公园。

They played three groups of participants each a different song and collected lots of information about them.

他们给三组参与者播放了不同的歌曲，并收集了很多关于他们的信息。