Hxen.com's tips：Every day persisted can learn English well!-->■Learn English Everyday■
surgery - n. performing an operation on the human body
department - n. a unit or area of an organization
pandemic - n. a contagious disease that spreads to many countries
nurse - n. one who assists a doctor
ventilator - n. a machine that helps a person breath
familiar - adj. something that is known already to someone
