一旦你需要帮助，给我打电话好了。

Should you need our help, just give us a ring.

youdao

它们不论昼夜都在那里，一旦你需要帮忙，它们都会在离你两英尺以内的地方。

They're always there night and day, and you've always got somebody about two feet away from you if you should need assistance.

youdao

一月下旬要保持日程表的开放性，当事情来临时，一旦你需要动起来，你就可以很快对事情做反应。

Keep your calendar open in the second half of January because that's when you need to roll, and you'll have to respond quickly to offers and events as they occur.

youdao

Once you know what pieces to look for, what mental constructs to reach for, can you realize all right I want to make some dancing figures go back and forth, I need to loop this way and loop this way and check if I'm on the edge and so forth.

一旦确定需要查找的部分,想要达到那种层次，你是否意识到,我想做出一些可以来回走动跳舞的人，我需要按这种方式那种方式让它转圈,并检查我是否,到了屏幕的边缘等等。

哈佛公开课 - 计算机科学课程节选