[单项选择]下列哪项关于胸腺和淋巴结的陈述是不正确的() A. 胚胎6~7周时,胸腺开始生成淋巴细胞 B. 胚胎11周时,淋巴结开始生成淋巴细胞 C. 胸腺有短暂的生成红细胞和粒细胞的作用 D. 源于卵黄囊的原始干细胞可直接分化成T淋巴细胞 E. 在胸腺内淋巴干细胞可分化成前T细胞和T细胞
参考答案:D
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第1题: [单项选择]Achieving a high degree of proficiency in English as a foreign language is not a mysterious______without scientific basic. A. process B. practice C. procedure D. program 参考答案:A 答案解析:名词辨析。practice意为“惯例”,program意为“项目”,均与句意不符;procedure意为“程序,步骤”,一般指按照规定、要求完成某事的过程,如legislative procedure
第35题: [单项选择]Lack of sleep can lead to ______. A. a sudden change in lifestyle B. good bodily condition C. the habit of falling asleep in front of the television D. a quick drop in both physical and mental condition 参考答案:D