第20题: [单项选择]{{B}}Passage One{{/B}}
{{B}}Questions 26 to 28 are based on the passage you have just heard.{{/B}} A. All sharks have teeth. B. A shark can have six rows of teeth. C. A shark can have hundreds of teeth. D. All sharks have extremely sharp teeth. 参考答案:D 答案解析:[听力原文]
Which of the following is NOT true about a shark’s teeth
[试题分析] 本题考查考生对信息细节的理解。
[详细解答]
第21题: [单项选择]佐剂的效应除外哪一项 A. 无免疫原性物质转变成有效的抗原 B. 改变循环抗体的类型 C. 增加抗体的量 D. 引起超敏反应 E. 改变抗原的特异性 参考答案:E