台湾籍旅美老师今天交给我们的句子是：

Unprotected sex and contaminated needles are the leading cause of transmission. It, fortunately, cannot spread through air, water, or casual contact.
没有防护措施的性爱、受感染的针头是病毒传播的首要原因。幸运的是它不能透过空气水分、或是一般接触来散播。