Al-Ludra oscillated, but not regularly: not like a pendulum; rather, like someone who is at a loss between two choices.
Al Ludra无规律的振荡，与单摆不同，更像是一个人在两个选择中周旋。
2
So a pendulum one meter long has a period of about two seconds.
因此1米长的钟摆，所用周期是2秒。
3
Easily crossed borders allow people to become what some researchers call "pendulum migrants", those who split their year between two different countries.