第28题: [单项选择]小儿肺部易发生感染的主要内因是() A. 呼吸中枢不健全 B. 黏膜纤毛运动差 C. 肋骨呈水平位,潮气量小 D. 肺含血量丰富,含气量少 E. 胸腔小而肺相对较大 参考答案:D 答案解析:肺泡数量少且面积小,弹力组织发育较差,血管丰富,间质发育旺盛,至肺含血量多而含气量少,易于感染。感染时易致黏液阻塞,引起间质炎症、肺气肿和肺不张。
第34题: [单项选择]It is generally agreed that the Internet has brought people together ________ . A. more than any invention B. than any other invention C. than any other invention has D. more than has any other invention 参考答案: