【单选题】He was supposed ____ us advice, but all he came up with were airy-fairy ideas.
【单选题】He was supposed to attend the meeting at 10:00, ( ) he arrived one hour late.
【单选题】患者女性, 24岁,因与朋友生气后自服敌敌畏150ml,因未及时发现,约近2个 小时才送医院。来急症科时患者出现肺水肿,惊厥,昏迷等严重症状,导致抢救 无效死亡。有机磷农药中毒的死亡原因是
【单选题】听力原文:W: Do you know when Jim comes back home? M: He was supposed to arrive this weekend, but actually he's coming the day after tomorrow. Q: What time will Jim come back? (3)
C.
The day before yesterday.
【简答题】蔬菜中有机磷农药残留过多,容易引起有机磷中毒,患者表现为肌肉震颤不止,严重者可能导致死亡。其原因是有机磷农药能抑制乙酰胆碱酯酶的活性,从而抑制乙酰胆碱(兴奋性递质)的分解。请利用下列实验材料验证有机磷农药的毒害作用。 实验材料:两个临时剥制的相同的青蛙神经—肌肉标本,放电装置,一定浓度的有机磷农药溶液,两个培养皿,生理盐水等。 实验步骤: (1)取两个培养皿,编号1(实验组)、2(对照组),加入等...
【简答题】蔬菜中有机磷农药残留过多,容易引起有机磷中毒,患者表现为肌肉震颤不止,严重者会死亡。原因是有机磷农药能抑制乙酰胆碱酯酶的活性,抑制乙酰胆碱(兴奋性递质)的分解。 (1)有机磷农药作用的结构是突触,此结构中兴奋传递的信号转换是电信号→________→__________。 (2)如刺激蛙的神经纤维,该处膜内外的电位情况是____________。 (3)请你利用下列实验材料来验证有机磷农药的毒害作...