金属指示剂的变色原理是指示剂本身及指示剂与金属离子所形成的络合盐，各有不同的颜色，而且有一定的pH适应范围。
参考答案：对
When his brother was to cross the street，he was knocked down by a truck and badly ________.
A．injured
B．damaged
C．harmed
D．destroyed
各类型休克的根本变化是（）。
A.代谢性酸中毒
B.脉搏快
C.尿量少
D.组织灌注不足
E.低血压
