在神经纤维动作电位的去极相，通透性最大的离子是（）.
A．Na+
B．K+
C．Cl-
D．Ca2+
E．Mg2+
参考答案：D
In my view，_______seems to be no possibility that we shall be able to afford that big a house .
A．that
B．there
C．it
D．this
试述柴油机“飞车”时的应急处理？
