第16题: [单项选择]Einstein’s theory of relativity seemed hard to believe at the time ______. A. when he first introduced B. that he first introduced it C. he first introduced D. which he first introduced it 参考答案:B 答案解析:[解析] 定语从句用法 at the time后接定语从句可以用when和that引导。故排除C项和D项。A项成分残缺,故排除。答案为B项。
第26题: [单项选择]预防破伤风首要的措施是() A. 彻底清洁消毒,敞开伤口,充分引流 B. 注射破伤风抗毒素 C. 镇静解痉 D. 注射破伤风人体免疫球蛋白 E. 做好伤口周围的消毒 参考答案:A 答案解析:破伤风杆菌为厌氧菌,在有氧情况下不易生长,因此应首先彻底清洁并敞开伤口,使伤口暴露,增加与空气中氧的接触。