问题
选择题
If _________, the bird flu would produce a powerful poison that would kill the patients.
A. not treat B not treated C untreated D. Both B and C
答案
答案：D
考查省略句，主从句的主语一致时，可以省略从句的主语和be动词，选B就是if it is not treated的省略，选C就是if it is untreated的省略，所以选D。