经济体制
参考答案：是指一定生产关系下生产、交换、分配和消费的具体形式。
With so many difficult problems ______, the manager felt worried all the time.
A．settled
B．having settled
C．settling
D．to settle
有关肥厚型心肌病的治疗正确的是
A．增强心肌收缩力
B．弛缓心肌为主
C．维持窦性心律
D．减轻心脏前负荷
E．重症梗阻性患者可做介入治疗
