[单项选择]（）the center of our planetary system was considered as heresy by the church in the Middle Ages. A. It is the sun and not the earth is B. That the sun and not the earth is C. Being the sun and not the earth is D. The sun and not the earth is
参考答案:B 答案解析:
该题是语法结构题，考查主语从句的用法。题干中已经有谓语结构be considered as heresy，句子缺乏的是主语。从几个选项来看，A、C和D都是主谓语结构，显然不能直接做句子的主
第24题: [单项选择]霍乱噬菌体裂解试验可用来区分霍乱弧菌的( ) A. 流行株与非流行株 B. O1群与O139群菌株 C. 古典型与E1Tor型菌株 D. 产毒株与非产毒株 E. E1Tor型与O139群菌株 参考答案:C 答案解析:[解析] 第Ⅳ组霍乱噬菌体裂解试验一般仅能裂解古典型，不裂解埃尔托生物型。
