spherical virtual confocal unstable resonator

例句：

1. 1. The planet Mercury is known for its spherical shape.
   水星以其球形而闻名。
2. 2. The sphere of influence of a planet is its spherical boundary.
   行星的势力范围是其球形边界。
3. 3. The spacecraft's design is spherical, meaning it has a smooth, rounded shape.
   太空船的设计是球形的，意味着它有一个平滑的、圆形的形状。