这是一次班级活动，让新老同学亲密无间地融合在一起。

It's a class move, allowing new and old to blend seamlessly.

《柯林斯英汉双解大词典》

有一次我和他一起去他乡下的家乡旅行。

Once I traveled with him to his hometown in the countryside.

youdao

不过，爷爷答应过我们，让我们跟你一起上去一次。

Grandfather has promised, though, to let us come up with you once.

youdao

And there are very few people that you can sit down and speak to for, like, eight hours at a time.

很少有人你可以坐在一起,一次就能聊天聊8个小时。

普林斯顿公开课 - 人性课程节选

You have to touch each of the 16 elements once as I go across the blackboard to actually merge them together, alright.

为了将这16个元素,合并到一起,对每个元素都只会用到一次。

哈佛公开课 - 计算机科学课程节选

There's even eating meditation, you did it once with me, and I've done this in other places where you take a raisin and you put it into your mouth, and you take a minute to eat this raisin.

甚至还有食禅，我们一起试过一次，我也在别的地方试过,你拿着一粒葡萄干,放入嘴中，花一分钟时间吃掉这粒葡萄干。

普林斯顿公开课 - 人性课程节选