讲解：
(just) in case (...)
以防；以防万一:
You'd better take the keys in case I'm out.
你最好带上钥匙以防我不在家。

be in quarantine
(为防传染的)隔离期；检疫:
The dog was kept in quarantine for six months.
这条狗被检疫隔离了六个月。

mandatory (for sb) (to do sth)
强制的；法定的；义务的
It is mandatory for blood banks to test all donated blood for the virus.
血库必须检查所有捐献的血是否含有这种病毒。

conncetion (between A and B) | ~ (with sth)
(两种事实、观念等的)联系,关联
Scientists have established a connection between cholesterol levels and heart disease.
科学家已证实胆固醇含量与心脏病之间有关联。

be vigilant
警觉的；警惕的；警戒的；谨慎
A pilot must remain vigilant at all times.
飞行员必须随时保持警惕。

instinct (for sth / for doing sth) | ~ (to do sth)
本能；天性:
Horses have a well-developed instinct for fear.
马天性易受惊吓。

revert to sth
回复；恢复:
After her divorce she reverted to her maiden name.
离婚以后,她重新用起娘家的姓氏。