Hxen.com's tips：Every day persisted can learn English well!-->■Learn English Everyday■
GPS – n. short for global position system, mapping based on the reception of signals from satellites in Earth's orbit
quarantine – n. a period in which people's movements are restricted because they might have been infected with disease
evaluate – v. to study or consider
pandemic – n. a disease spreading over a wide area and affecting large numbers of people
uncharted – v. unexplored or unknown
