Hxen.com's tips：Every day persisted can learn English well!-->■Learn English Everyday■
symptom – n. a change in the body or mind which indicates that a disease is present
asymptomatic – adj. medical: having or showing no symptoms of disease
quarantine –n. a situation of being kept away from others to prevent the spread of a disease
isolation – n. the state of being in a place or situation that is separate from others : the condition of being isolated
transmission – n. the act or process by which something is spread or passed from one person or thing to another
tremendous – adj. very large or great
