某患者因与人争吵后服用敌敌畏,引起有机磷中毒,被给予大量阿托品治疗。阿托品对有机磷中毒的下列哪种症状无效
A.大汗
B.肠痉挛
C.心率减慢
D.肌束颤动
E.瞳孔缩小
参考答案:D
下列关于铁的化学性质的描述中,正确的是( )
A.很活泼,在空气中点燃,会剧烈燃烧,火星四射
B.比较活泼,铁与酸反应的程度比锌与酸反应剧烈
C.不活泼,铁不能将含铜化合物中铜置换出来
D.比较活泼,常温下,铁在潮湿的空气中会生锈
Two dogsled teams raced across a 300-mile course in Wyoming. Team A finished the course in 3 fewer hours than did team B. If team A’s average speed was 5 miles per hour greater than that of team B, what was team B’s average speed, in miles per hour ?()
A. 12
B. 15
C. 18
D. 20
E. 25