第28题: [单项选择]酚妥拉明用于治疗顽固性充血性心力衰竭的主要原因是() A. 扩张外周小动脉,减轻心脏后负荷 B. 抑制心脏,使其得到充分休息 C. 扩张肺动脉,减轻右心负荷 D. 兴奋心脏,加强心肌收缩力,使心率加快,输出量增大 E. 扩张肺小动脉,减轻右心负荷 参考答案:A 答案解析:酚妥拉明通过阻断α受体和直接舒张血管,使外周阻力降低,血压下降。反射性加强心肌收缩力,能舒张心力衰竭时小动脉和小静脉的反射性收缩,使外周阻力降低,心脏负荷降低,心输出量增加,从而逆转充血性心力衰竭时的
第30题: [单项选择]A) Because she leaves her mother. C) Because she is iii. B) Because she is in the hospital. D) Because her mother is iii. 参考答案:D 答案解析:[听力原文] M: Why are you feeling down today W: My mother was sent to hospital yesterday. Q: