visible arc的意思|示意

Visible light telescopes can resolve a piece of sky just a few arc seconds across — at least 60 times a smaller patch of sky than can be resolved with the human eye.

光学望远镜在数角秒内就能获取一张星空图—至少比肉眼能获取的大60倍。

Indeed, the yellow tower Arc DE Triomphe, the Louvre in the shade, white Mengma Sacred Heart Church are clearly visible, colorful.

的确，淡黄色的凯旋门城楼、绿荫中的卢浮宫、白色的蒙马圣心教堂都清晰可见，色彩斑斓。

Are there any visible arc marks on upper surfaces LPS rods?

避雷针的上部表面是否有可见的电弧放电痕迹？