Backal口腔锭
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
backing-off铲,退绕
back breaking劳累至极的
backslash key反斜线键
back and fillvi.看风使舵前进以避开障碍(反复无常)
back-boilern.热水器
backspin roll传动托棍
back stabbing暗箭伤人
back sb. up给某人撑腰打气
backstop tone后定位夹钳
"he is always backslapping his colleagues at staff meetings"