So they built a system of canals to bring water down from the mountains.

VOA: special.2009.06.04

Remember, because that 1 s orbital is all the way down in terms of if we're thinking about an energy diagram, we're all the way down here, so we have a huge amount of energy we have to put into the system in order to eject an electron.

还记得吧，因为1，s，轨道在能量示意图里,是在最底部的，我们要一直到最下面，所以我们要向这个系统注入非常大的能量,才能打出一个电子。

麻省理工公开课 - 化学原理课程节选

But they have really had a big scaling down of the mass transit system this year.

但是今年确实大幅度削减了公共交通。

纽约的公共交通 - SpeakingMax英语口语达人