在20年的绝大部分时间里，我一直在撰写和谈论太空飞行，突然将兴趣转向海洋深处，确实显得很奇怪。

As I have been writing and talking about space flight for the best part of 20 years, a sudden switch of interest to the depth of the sea does seem peculiar.

youdao

如果在飞行中它们失去了能量，它们可以自旋下降并着陆而无需承受任何伤害，因为它们弹性构造可以使伤害转向。

If they lose power while flying, they can autorotate down and land without sustaining any damage due to their flexible structure that deflects upon impact.

youdao

但是当向前飞行时，它的旋翼将转向直升飞机的前方(如此一来，就变成朝向迎面而来的空气)，经过叶片上方的气流将比经过叶片背面的气流产生更大的升力。

But when flying forward the air passing over the blade that is advancing to the front of the helicopter (and so into oncoming air) provides more lift than the one that is retreating to the back.

youdao