dismount
单词辨析：
指人或事物从高处向低处移动。
The old lady slowly descended the stairs.
这位老太太慢慢走下台阶。
He descended the ladder with the help of his mother.
在妈妈的帮助下，他从梯子上爬了下来。
The sun descended behind the hills.
太阳下山了。
指人经过一段行程之后，从交通工具上下来，常与介词 from 连用。
The visitors alighted from the airplane.
游客们下了飞机。
We arrived just as he alighted from the train.
他刚下火车，我们就到了。
特指从马背、自行车或者摩托车上下来，常与介词 from 连用。
He dismounted from his motorcycle.
他从摩托车上下来了。
She dismounted and took the horse's bridle.
她下了马，拉着马笼头。
相关例句：
From the Chinese, we borrowed the colourful proverb He who rides a tiger is afraid to dismount, meaning that if you start on a dangerous enterprise, it is often easier to carry it through to the end than to stop halfway.
从汉语，我们借用了这条活灵活现的谚语骑虎难下，意思就是如果你开创了一项危险而又艰巨复杂的事业，与其半途而废，倒不如进行到底会更顺利一些。
When need calls it, the Mailed Knights would often dismount to help defend or assault a fortification.
一旦战事需要，链甲骑兵经常跨下马背充任步兵，协防或助攻城邑。
When a back and forth handle on the boring bar is rotated, the boring bar falls back and the pin can quickly dismount the knife.
当转动机床镗杆进退手柄使镗杆向后退时，销子就可快速的把刀具卸下。
The cavalry officer gave the order to dismount.
骑兵队长传达下马的命令。
The appearance of any plane was the signal to dismount and scatter.
一经发现飞机，就得下车疏散。
Bicyclists are expected to dismount, and trucks and cars to slow down, out of respect.
出于尊敬，骑自行车的人要下车，而卡车和轿车则会减慢速度。