lengthsn.长度，指距离或时间（length的复数）lengthn.长度；时间长短；距离；一段；距离的测量单位length by length一步一步地,一分一分地length difference长度差length of top bud顶芽长度length of the tow拖船,队长度,拖缆长度Length of cranial颅长length of a stick手杖的长度length of sleeper轨枕长度length of tangent切线的长length proportion长度比例length of plateau坪长