第8题: [单项选择]胚胎造血首先出现在 A. 胸腺 B. 肝 C. 卵黄囊 D. 骨髓 E. 淋巴结 参考答案:C 答案解析:[解题思路] 小儿造血分为胚胎造血和生后造血两个阶段。胚胎造血部位不同,中胚层造血,妊娠造血首先出现在卵黄囊,其内出现血岛,主要为不成熟的红细胞,至10~12周卵黄囊造血消失。继为肝造血期,可持续至出
第28题: [单项选择]Which of the following is NOT mentioned as a step to control smoking A. Forbidding smoking in all public places. B. Collecting a special tax on cigarettes. C. Banning cigarette advertising from radio and TV. D. Requiring a warning on each cigarette package. 参考答案:A