three defensive lines
Facing mounting pressure from imported cases，China has set up “three defense lines”, which effectively prevents the outbreak (爆发) from hitting the country again. The first defense line is at the ports of entry where international travelers are required to receive medical checkups and report their travel history. The 14-day quarantine (隔离) is the second defense line. Even if the first two lines of defense both fail, medical staff and facilities around the country would effectively handle infected patients, said Wu Zunyou, an epidemiologist (流行病学家) at the Chinese Center for Disease Control and Prevention, on March 24.