第18题: [单项选择]AaBBCc与AABbCC的个体杂交,后代的表现型有() A. 8种 B. 4种 C. 1种 D. 16种 参考答案:C 答案解析:AaBBCc与AABbCC的个体杂交,后代表现型种类有1×1×1=1种。
考点:基因的自由组合定律
点评:难度中等,解题的关键是明确基因自由组合定律的实质。
第19题: [单项选择]What in the writer's opinion, happens to a scholar who shares his ideas with his colleagues A. He gains recognition for his achievements. B. He attracts large numbers of students. C. He risks his ideas being stolen. D. He is considered slightly mad. 参考答案:A 答案解析:[精析] 作者观点 文章一开始:就点出学者和学生经常是伟大的旅行家。学术活/运动(周游活动)是世界上经济和社会发展的根本需要。第二段提到分享。只有承认后才能分享。分享才能促使经济社会发展。