单选题A．0期去极速度快、幅度高 B．4期自动去极C．两者都是 D．两者都不是

单选题肾上腺皮质功能亢进时不出现

单选题脾在哪种白血病时肿大得最显著

单选题During recent years we have heard much about "race": how this race does certain things and that race believes certain things and so on. Yet, the (1) phenomenon of race consists of a few surface indications. We judge race usually (2) the coloring of the skin: a white race, a brown race, a yellow race and a black race. But (3) you were to remove the skin you could not (4) anything about the race to which the individual belonged. There is (5) in physical structure, the brain or the internal organs to (6) a difference. There are four types of blood. (7) types are found in every race, and no type is distinct to any race. Human brains are the (8) . No scientists could examine a brain and tell you the race to which the individual belonged. Brains win (9) in size, but this occurs within every race. (10) does size have anything to do with intelligence. The largest brain (11) examined belonged to a person of weak (12) . On the other hand, some of our most distinguished people have had (13) brains. Mental tests which are reasonably (14) show no differences in intelligence between races. High and low test results both can be recorded by different members of any race. (15) equal educational advantages, there will be no difference in average standings, either on account of race or geographical location. Individuals of every race (16) civilization to go backward or forward. Training and education can change the response of groups of people, (17) enable them to behave in a (18) way. The behavior and ideals of people change according to circumstances, but they can always go back or go on to something new (19) is better and higher than anything (20) the past.

单选题肾梗死一般不会导致

单选题血中激素浓度很低，而生理效应十分明显是因为( ) A．激素的半衰期长 B．激素的特异性强 C．激素作用有靶细胞 D．激素间有相互作用 E．激素有高效能放大作用

单选题下列肝细胞坏死的病变中，可以发生结节状再生的是

单选题 正常人眼在视近物时的视觉调节过程包括（ ） A、晶状体变凸，瞳孔缩小，视轴会聚 B、晶状体变凸，瞳孔不变，视轴会聚 C、晶状体变凸，瞳孔缩小，视轴不变 D、晶状体不变，瞳孔缩小，视轴会聚 E、晶状体变凸，瞳孔扩大，视轴会聚

单选题缩血管神经节后纤维释放的递质是( ) A．肾上腺素 B．去甲肾上腺素 C．乙酰胆碱 D．5-羟色胺 E．组胺

单选题 小肠分节运动的主要作用是（ ） A、快速推进食糜从小肠上段向下段运行 B、使食糜存留时间延长，利于食物的充分消化和吸收 C、将食糜从十二指肠一直推送到小肠末端 D、使食糜与消化液充分混合，便于化学消化的进行 E、减少食糜与肠粘膜接触的机会，以加强食糜的推进

单选题“入芝兰之室，久而不闻其香”描述的是感受器的哪种特性______

单选题促进男性副性征出现的激素是( ) A．绒毛膜促性腺激素 B．雌激素 C．孕激素 D．雄激素 E．催乳素

单选题某人血清中有抗A、抗B凝集素、红细胞膜无D抗原，其血型属于( ) A．AB型，Rh阴性 B．O型，Rh阳性 C．AB型，Rh阳性 D．O型，Rh阴性

单选题在所有消化液中，消化能力最强和最主要的是

单选题对于血管内皮细胞无刺激作用的是

单选题急性菌痢的病理学形态取决于

单选题不符合泡膜细胞瘤的描述是

单选题A．细动脉玻璃样变B．细动脉纤维化C．细动脉淀粉样变性D．细小动脉纤维素样坏死

单选题组织液的生成与有效滤过压密切相关，有效滤过压等于

单选题正常机体维持动脉血压相对稳定的反射是______