十几二十年前，你买到的牛奶会装在可回收、可重复灌装的玻璃瓶里，许多人也自愿做回收工作。

Ten or twenty years ago, you could buy milk in returnable, refillable glass bottles, and many people recycled voluntarily.

youdao

当我走到距离她几英尺远的时候，我伸出手去，想去碰她的肩膀，可马上就把手收回来了。

When I got a couple of feet from her, I reached out my hand to touch her shoulder, then immediately pulled it back.

youdao

一个意料外的障碍是，尽管在相当近的距离内传输效率很高，可一旦和传输器的距离达到几毫米，效率就会跌到零。

The snag, however, has been that while efficiency is good at close contact, it can drop to zero at even a few millimetres from the transmitter.

youdao

So to be clear, we expect most students to very comfortably pursue the standard edition of the P set, but for this particular P set, and we have about 150 or so of these out on the hallway, and we'll have them at office hours throughout the coming week--this is a little logic board ; with lots of sensors; the sound sensor, a light sensor, a little joystick and the like.

我希望我们大多数同学,研究问题集的标准版本，可编程版有个特殊的问题集，我们会在接下来的几周里，在办公时间为大家做解答,这是个小的逻辑板,上面有很多传感器;,包括声音传感器，光传感器，小操作杆等。

哈佛公开课 - 计算机科学课程节选