下列关于人体免疫的叙述，正确的是（）。
A.T细胞受到抗原刺激后可直接转变为效应T细胞
B.T细胞受到抗原刺激后增殖分化成浆细胞并产生抗体
C.过敏反应是人体特异性免疫应答的一种异常生理现象
D.人体内的巨噬细胞只参与非特异性免疫过程
参考答案：C
解析：特异性免疫包括体液免疫和细胞免疫。 A项.T细胞受到抗原刺激后可增殖、分化为效应T细胞，错误； B项，B细胞受到抗原刺激后可增殖、分化成浆细胞并产生抗体，错误； C项.过敏反应是指已产生免疫的机体在再次接受相同抗原刺激时所发生的组织损伤或功能紊乱的反应，正确； D项，人体内的巨噬细胞既参与非特异性免疫过程，也参与特异性免疫过程，错误。
 Two teachers were sitting in the teachers' room. For a moment there was silence. Then one of them, Miss Smith, said, "I'm afraid I'd have to fail him! I just can’t let him 16 . " "Now Alice," said her friend, Mrs Jackson, "is he so terrible a student?" "That's just the trouble!" the other woman answered, "Tom was ever my 17 student. The problem is that he is so lazy that he never gets his work done. He hasn't handed me a piece of homework for three 18 !" Mrs Jackson had never seen Miss Smith so 19 before. "Have you had a word with him about it?" she asked. "Why should I? Every student must hand in homework. I made 20 very clear on the first day for class. I don't know what has happened. When the lessons started, he did so well that I 21 thought about asking the school to give him a scholarship(奖学金). But now he often sleeps in class! I've never seen such a 22 in a student." "You should have a talk with him. Give him a chance. " Miss Smith spoke to Tom and learned all about it. He was studying all day and working most of the night in a factory to 23 for his schooling. Of course he was 24 in class and sometimes could hardly 25 awake. Miss Smith soon asked the school to give him a scholarship and he was able to devote himself to his lessons again.
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