标本采集前影响血液成分变化的生理可控因素主要有() ["情绪","近期食谱","运动","体位改变","性别"]
手术患者从术前8~12小时禁食,4小时禁水是为了() ["减少术后感染","防止术后腹胀","防止吻合口瘘","防止术后伤口裂开","防止麻醉或术中呕吐"]
大头瘟临床基本特征是() ["A.发热恶寒","B.发热头面,赤肿大","C.但热不恶寒","D.咽喉疼痛","E.头部发热"]
为了安装活塞和连杆总成,须使曲轴连杆轴颈处于()位置。 ["下止点","上止点","中间位","任意位置"]
测定小麦杂质时,规定的绝对筛层的孔径为()。 ["1.5mm","2.0mm","3.0mm","5.0mm"]
历史上有哪些五次对中国绘画发展产生重大影响的理论及代表人物?