back lighting 背景照明；逆光照明back light [車輛] 后燈；背景光back level hang [體育]背水平懸垂back levee march [能源科學技術]堤后草本沼澤back levee 支堤back length 后面長度back leg 后床腿；背面支柱back layer [感光] 攝影背面層back lash 齒隙；間隙；側隙；絲隙back lamp [車輛] 尾燈back kick 后踢back judge back jam [體育]背樽back jack-knife stroke [體育]后鐮刀式跳水back ironwood [農業(yè)科學]月桂葉木犀欖木back into the darkness back into 倒車撞上（某物）back interpolation formula [能源科學技術]后插公式back inlet gully [土木建筑工程]后部進水集水井back injury 背部損傷