皮带机上哪些部位容易绞伤人？
参考答案：
皮带机上有头部区域（对轮接手、头轮、增面轮），尾部区域（尾轮、反向轮）上下托辊及卸料小车工作区域。
(2012·宁波高二检测) Zhang Lin was addicted to computer games during his last year in high school, otherwise he _______ a student of Beijing University.
A．would have been
B．should be
C．has been
D．had been
轮带下垫板的厚度一般为（）。
A.10-20mm
B.20-50mm
C.50-70mm
