题目

He did not want to (显露) his fears and insecurity to anyone. 答案：【1】expose1.   如图工人用动滑轮将重1000N的货物匀速提高2m,所用时间为10s。若不计绳重、动滑轮的重和摩擦，则在此过程中A．拉力F做的功为1000J，功率为500WB．拉力F做的功为2000J，功率为500WC．拉力F为500N，绳子自由端移动距离为2mD．拉力F为500N，绳子自由端移动距离为4m