第7题: [单项选择]疟原虫感染者可产生的免疫是()。 A. 先天性免疫 B. 带虫免疫 C. 终身免疫 D. 消除免疫 E. 足以防止每次感染的保护性免疫 参考答案:B 答案解析:人类感染疟原虫后产生的免疫力,能抵抗同种疟原虫的再感染,但同时其血液内又有低水平的原虫血症,这种免疫状态称为带虫免疫(premunition)。
第22题: [单项选择]What do we learn about prisoners in Britain A. They are encouraged to do maintenance for the training centre. B. Most of them get paid for their work. C. They have to cook their own meals. D. They can choose to do community work. 参考答案:B