彗星的

例句：

1. 1. The comet was visible in the sky for several days.
   这个彗星在天空中可见数日。
2. 2. Scientists have been studying comets for years to understand their origins.
   科学家多年来一直在研究彗星，以了解它们的来源。
3. 3. Comets are fascinating objects that scientists study for clues about our solar system's past.
   彗星是令人着迷的天体，科学家们研究它们是为了寻找有关我们太阳系过去的秘密线索。