小动脉收缩，外周阻力增加时
A．K+外流B．Ca2+内流和K+外流C．Na+内流D．Ca2+缓慢内流E．Na+和Ca2+内流
参考答案：B
Could you please tell me ______ just now?[ ]
A. what's happened
B. what's happening
C. what happened
D. what was happened
可在双层底内装载（）来调节船舶吃水、纵横倾及稳性。
A.淡水
B.燃料
C.货物
D.压载水
