同一车轴上组装两个车轮轮辋宽度差：铸钢车轮不大于（）。
A.4mm
B.5mm
C.6mm
D.7mm
参考答案：B
高架绝缘斗臂车在110kV设备上工作，绝缘臂的有效长度应该多长？
— Have you seen ____ pencil? I left it here this morning．
—Is it _____black one? I think I saw it somewhere
A．a; the
B．the; the
C．the; a
D．a; a
