人工提、放钻机时，提升梁必须使用直径大于（）的圆钢或木梁。
A.50mm
B.100mm
C.200mm
参考答案：C
在△ABC中，化简：bcosC+ccosB=（ ）。
The world's greatest sporting event, the Olympic Games, upholds the amateur ideal that ______matters is not winning but participating.
A．anything
B．it
C．what
D．everything
