他们可以发球、扣球、拦网、反扣，都同样熟练。
They could serve and hit the ball, block it at the net or return it with equal facility.
公锥与正、反扣钻杆及其他工具配合使用，可实现不同的打捞工艺。
The taper tap can effect different fishing operations when equipped with RH thread or LH thread drill pipes and other tools.
为了克服剪钉式和反扣式两种安全接头的不足，研制出一种滑套式井下安全接头。
To overcome the shortcomings of the shear pin type joint and left-hand thread type joint, a sliding sleeve subsurface safety joint is developed.
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