哪些不是重症病毒性心肌炎（）
A.阿斯综合征发作
B.严重充血性心力衰竭
C.心源性休克
D.持续性室速
E.心电图广泛T波低平
参考答案：E
Beta blockers work on some physical and emotional symptoms because they ______.
A．fool a person into a healthier stance
B．interfere with the effects of adrenalin
C．produce side effects worse than the symptoms
D．primarily change human thought processes
简述封山育林的作用。
