VOA慢速英语:美国学校似乎不能决定重开校园

district – n. an area established by a government for official government business

pandemic – n. an occurrence in which a disease spreads very quickly and affects a large number of people over a wide area or throughout the world

quarantine – n. the period of time during which a person or animal that has a disease or that might have a disease is kept away from others to prevent the disease from spreading

hot spot – n. a zone or area in which something is very active

positive – adj. showing the presence of a particular germ, condition, or substance

protocol – n. a system of rules that explain the correct conduct and procedures to be followed in formal situations