道口工要熟悉各种设备及防护备品的标准和技术要求。（）
参考答案：对
Playing balls together is a kind of activity_____ every player needs to be well-cooperated together.
A．which
B．where
C．that
D．what
A．a为动滑轮，B端钢缆受到滑轮组的拉力大小约为3G
B．a为动滑轮，B端钢缆受到滑轮组的拉力大小约为G
C．a、c为动滑轮，B端钢缆受到滑轮组的拉力大小约为3G
D．a、c为动滑轮，B端钢缆受到滑轮组的拉力大小约为G
G
G