cosmic expansion

例句：

1. 1. The universe is expanding at an ever-increasing rate.
   宇宙正在以越来越快的速度膨胀。
2. 2. Astronomers have discovered that the universe is expanding.
   天文学家已经发现宇宙正在膨胀。
3. 3. Cosmologists believe that the universe is expanding due to the Big Bang theory.
   宇宙学家相信宇宙膨胀是由于大爆炸理论导致的。