pestilential qi

例句：

1. 1.The disease is known to be highly contagious.
   这种疾病已知具有很强的传染性。
2. 2.The bacteria is known to be pathogenic.
   这种细菌已知是致病的。
3. 3. The virus is known to be infectious.
   这种病毒已知是传染性的。