Pre-solar grains are now estimated to make up a small part — only 100 parts per million — of the comet.
Pre-solar grains are now estimated to make up a small part — only 100 parts per million — of the comet.
前太阳系颗粒估计填补了一小部分彗星成分——只有万分之一。
Pre-solar grains are now estimated to make up a small part — only 100 parts per million — of the comet.
前太阳系颗粒估计填补了一小部分彗星成分——只有万分之一。