铜母线接头表面搪锡是为了防止铜在高温下迅速氧化或电化腐蚀以及避免接触电阻的增加。
参考答案：对
There was _____ woman in the room, sitting and looking at me in the dark.
A．a 80-year-old
B．an 80-year-old
C．a 80-years-old
D．an 80-years-old
从改革开放到现在，我国社会已进入（）收入阶段。
A.低等
B.中上等
C.中等
D.高等
