中文原文：

过去，人们普遍缺乏关于预防传染病的科学知识。

错误译文：

In the past, the people generally lacked of the scientific knowledge about how to prevent infectious diseases.

正确译文：

1)In the past, the people generally lacked the scientific knowledge about how to prevent infectious diseases.

2)Formerly, the people were generally lacking in the scientific knowledge on how to forestall contagious diseases.

3) In the past, the people were generally short of the scientific knowledge concerning the prevention of infectious diseases.

4) Previously, the general public had insufficient scientific knowledge in connection with the prevention of epidemic diseases.

翻译加油站：

表示“缺乏”，可以用to lack。它是及物动词，后面直接跟宾语，不需要用介词of。表示“缺乏知识”，常用to lack the knowledge; to be lacking in the knowledge; to be short of the knowledge; to have insufficient knowledge等方式。注意： infectious disease是通过空气的传染病；contagious disease是通过接触的传染病。而epidemic disease是流行病。“预防疾病”可以用to prevent a disease; to forestall a disease或the prevention of a disease表示。

“缺乏知识”，具有“所知甚少”的意思，可以用to know very little; not to know much; to have little knowledge等方式表示。例如：

1. 几个月以前，甚至连专家都对非典所知甚少。
1)A few months ago, even the experts knew very little about SARS.
2)Several months ago, even the experts didn't know much about SARS.
3)Some months ago, even the specialists had very little knowledge about SARS.

“缺乏知识”，具有“无知”的意思，可以用to be ignorant of/about等方式表示。例如：

2. 现在许多人仍然对免疫相当无知。
Now many people are still rather ignorant of immunity.

3. 一开始，医生们对如何治疗非典一无所知。
1)Initially, the doctors were totally ignorant about how to deal with SARS.
2)In the beginning, the doctors were quite ignorant about how to treatSARS.