二档

leap second───闰秒

leap seconds───闰秒

arcsecond───角秒

arcseconds───弧秒

femtosecond───n.飞秒，毫微微秒

microsecond───n.微秒；[计量]一百万分之一秒

nanosecond───n.纳秒；十亿分之一秒

to second───到秒

zeptosecond───泽普托松

There are 4 bunks, a clutter of science gear, and - through a short connecting corridor — THREE LINK UNITS in the second module.───这里有4个床位，一些摆放杂乱的工具，和——穿过一段短小的连接回廊——第二个舱室里有三个链接单元。

clutch broke, the car was locked into second gear.───离合器损坏了后,那辆轿车被锁在了二档。

This is why, for most vehicles, low-range second is the ideal gear to tackle the steep stuff.───这个原因，对于大多数车辆来说，低速二档是用来征服陡峭山坡的理想档位。

This is gear knob: neutral gear, first gear, second gear, third gear, fourth gear, fifth gear, retreat gear.