| 释义 |
〔pulley〕A simple machine consisting essentially of a wheel with a grooved rim in which a pulled rope or chain can run to change the direction of the pull and thereby lift a load.滑轮装置：一种有一个拉绳或链子穿过的有槽的轮子且通过改变拉力的方向而拉起重物的简单机械〔crossbow〕A weapon consisting of a bow fixed crosswise on a wooden stock, with grooves on the stock to direct the projectile.弩：一种包括有一个交叉固定在木柄上的弓的武器，木柄上有槽以释放弓箭 |