在电力系统非正常状况下，用户受电端的电压最大允许偏差不应超过额定值的±10%。
参考答案：对
---How could you _______ my sister so easily in the crowd ?
---Because she stood out in a red dress.
A．pick out
B．pick up
C．take up
D．take out
表示病毒复制活跃，传染性强
A．HBsAgB．抗-HBsC．HBeAgD．抗-HBeE．抗-HBc
