backmen后卫backn.后面；背脊；靠背；后背；后卫vt.支持；后退adv.向后地adj.向后的；后面的；偏远的；过时的；积欠的back-and-foot technique用背和脚作支点的登攀法back sliding step technique背向滑步技术back filling behind abutment台背回填Back - propagation network反向传播网络back-connected stone panel背部连接面板BACK POCKET HEIGHT AT CENTERback-leaning angle of body躯干后倾角backcross quantitative trait回交定量性状Back and Forth in Bangladesh孟加拉的前进与倒退backscattered electron image背散射电子像