诊断急性肺水肿的依据是（）
A.劳力性呼吸困难
B.端坐呼吸
C.肝颈返流征阳性
D.颈静脉怒张
E.神志不清
参考答案：B
Schools allow students to do at least one hour's sports every day after school. [ ]
A. would
B. might
C. should
D. could
弹簧操动机构在直流电源消失的情况下也可手动合、分操作。
