100 BILLION stars in our galaxy 282020-08 2 88 keys on a grand piano 522020-08 3 86,400 seconds in a day 482020-08 4 60 seconds in a minute 492020-08 5 52 cards in a pack 262020-08 6 50 stars on the USA flag 362020-08 7 7.5 BILLION is the estimated population of the Earth ...
题目If you look up at the sky on a clear and dark night,you'll see more stars than your eyes can count.Most of these stars have planets,similar to our own,orbiting them.With so many celestial bodies floating out in space,you can't help but question whether other...
"Going into the research, astronomers had observed that the number of Milky Way stars diminishes rapidly about 50,000 light years from the center of the galaxy, and then a ring of stars appears at about 60,000light yearsfrom the center," said Xu. "What we see now is that this apparent...