动词 arc:

1. form an arch or curve

arco以弓拉arcn.弧；弧形物vi.形成电弧；按弧形轨迹行进Arceleanu阿尔切莱亚努Arctornisn.白毒蛾属arc power电弧功率Arcudeanu阿尔库代亚努arctation孔道狭窄arccosinen.反余弦arc shield电弧罩Arciniegas阿西涅加斯arcmeltingn.电弧熔化arc bridge拱桥

1. The sun appears to move in an arc across the sky.
   太阳看起来在天空以弧线运行。
2. An early instrument for measuring altitude of celestial bodies, consisting of a90= graduated arc with a movable radius for measuring angles.
   象限仪用来测量天体纬度的一种早期工具，由一个有90度刻度的圆弧和一个用来测量角度的可移动的半径构成