左心衰竭最早出现的症状是（）
A.夜间阵发性呼吸困难
B.心源性哮喘
C.端坐呼吸
D.咳粉红色泡沫痰
E.劳力性呼吸困难
参考答案：E
Mum, you really need to have a rest! You in the kitchen ever since you came back home three hours ago.
A．had worked
B．were working
C．have been working
D．worked
细菌的基本形状有哪些？
