A. What should I do B. Thank you, mom. C. Where have you been D. Yes, he is. E. What was wrong with him F. Were you sick G. Where is the hospital H. I’m sorry to hear that.
A. 对 B. 错
A. 有病原体 B. 有传染性 C. 有流行病学特征 D. 有感染后免疫 E. 以上都是
A. 胎儿期 B. 幼儿期 C. 童年期 D. 青春发育期 E. 青年期
A. 地方性甲状腺肿 B. 克汀病 C. 水俣病 D. 克山病 E. 氟病
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