.There are over 58000 rocky objects in _______space,about 900 of which could fall down onto ______earth。
She is not used to __________ like that.
The new rule has been working effectively since it __________.
As a result, these endangered animals may even __________.
__________ time goes on, our country becomes more and more powerful.
The newly discovered star was named __________ a Chinese astronomer __________ honor of his contributions to astronomy.