静电是由于两种（）物质相互接触、分离、摩擦而产生的。
A、相同
B、不同
C、相似
D、相异
参考答案：B
日本群岛附近的大渔场是[ ]
A．北海道渔场
B．北海渔场
C．纽芬兰渔场
D．舟山渔场
Which finding is considered normal in a neonate during the first few days after birth（）
A. Weight loss of 25%.
B. Birth weight of 2,000 to 2,500 g.
C. Weight loss then return to birth weight.
D. Weight gain of 25%.
