1. If the term sounds unscientific to 20th-century ears, let us remember there is a definite connection between marshy lands and malaria, and that the naming of the disease itself perhaps represents a praiseworthy effort of observation.
    尽管对20世纪的人来说，“坏空气”一词听起来不科学，我们应该记得沼泽地和疟疾之间有着肯定的联系，因此，“坏空气”一词自身也许代表着一种值得称道的观察。

2. Which hopes to use human DNA to build specialized proteins that may have some value as disease-fighting drugs.
    医学界希望能用人类脱氧核糖核酸（DNA）制成特别的蛋白质，这些蛋白质具有某种抗病药物的价值。

3. Fever and inflammation are phenomena of disease.
    发烧和炎症是疾病的症状。

4. Fever and inflammation are phenomena of disease.
    发烧和炎症是疾病的症状。

5. For instance, tuberculosis, once a dangerous killer, was cured. Now the disease is appearing again.
    例如，曾经是危险杀手的肺结核原本已被消灭，但是现在这种疾病又死灰复燃了。