胺碘酮延长不应期作用是通过阻滞
A．0相Na+内流
B．3相K+外流
C．0相Ca2+内流
D．4相Na+内流
E．4相Ca2+内流
参考答案：B
下列临床情况最易引起急性左心衰竭的是（）
A.频发室性期前收缩
B.二尖瓣腱索断裂
C.Ⅰ级高血压
D.反复发作的肺栓塞
E.慢性持续性房颤
-Many people are in great need of extra food.
-Yes.It is a challenge to________all their needs.[ ]
A．satisfy
B．gain
C．practise
D．produce
