The crystalline satellite was an enormous unmanned sphereof brilliant engineering, approximately five miles in diameter.
水晶卫星是一个巨大的无人驾驶的辉煌工程，直径约五英里。
2
The diameterof a sphere is four times the focal length of a concave mirror cut from it.
凹面镜如果是从圆球上切下来的，圆球的直径会是凹面镜焦距的四倍。
3
The results show that appropriate amount of Bi can decrease the diameterof graphite sphere, increase the number of graphite sphere, strengthen the low-temperature toughness.