试题题干
WORD FORMATION
Complete the following sentence with the proper form of the word in the bracket.
(sick) Doctors of that time knew very little about causes of
or ways of preventing it.
参考答案
试题解析
此处缺少名词。
or前后接的成分是并列的，所以or前面应该也是名词形式。因此，变sick为名词形式为sickness。
句意：那个时代的医生关于疾病的起因或者如何预防疾病都知道得很少。