Top News Stories of Two-Thousand-Four 01-01永远在一起的英文I'm Steve Ember with In the News in VOA Special English.This week we tell about some of the biggest news stories of two thousand four. We start in As
Equation for calculating hydraulics1. 喷嘴压降(pressure drop across bit nozzle)B= W Q2 /10858 A2 B:喷嘴压降(pressure drop across bit nozzle):PSI。 W:泥浆密度(mud weight):PPG。 Q:泵排量(flow rate):GPM。 A:喷嘴总面积(total f