Chisels, screw drivers and pointed tools should never be carried in your pockets.
凿子、螺丝刀及带尖端的工具绝不可放在口袋中携带。
2
It is pointed out that for the same specification of the pump, to enlarge the screw Angle can increase its flow rate.
对同一规格的产品，指出可以采用增大螺旋角的方法提高其流量。
3
He has perfected a technique of etching letters onto microscopic surfaces-including the tip of a screw, the head of a pin and the pointed end of a paperclip.