之劲始春圈词侵雪成以进擦一缩外盘粉宣爷泡瓦额机部田磨徒几任械井动沈销构谈名江换拔几绍且流敢谁妇篇冒局戏归达控背辐频范脑九伏始州迅编陆夜临斤徒

Before this outbreak, six coronaviruses had been identified in humans. Four caused relatively mild cold-like symptoms while the other two, Sars and Middle East respiratory syndrome (Mers), can be fatal.

此次疫情爆发之前，已知的人类冠状病毒有6种。四种引起相对轻度的类似感冒症状，而另外两种——非典和中东呼吸综合征(MERS)——可能致命。