钻井液受污染后,加入电解质清除污染()。 ["A、有助于降滤失","B、不影响","C、不利于降滤失","D、无法判断"]
滑车滑轮的直径是指:() ["滑轮外边直径","滑轮内边直径","滑轮索槽底部的直径","滑轮孔直径"]
吊杆装置中,钢丝动索用的滑轮直径与绳索直径之比应为:() ["6","8","13","10"]
网络营销站点的功能?
一铁滑车滑轮直径为300mm,则可配用纤维绳的最大直径为:() ["60mm","50mm","100mm","75mm"]
简述功率MOSFET的特性。