astronaut(太空人) : a person who travels beyond the earth's atmosphere; also : a trainee for spaceflight astronomer(天文學家) :a person who is skilled in astronomy or who makes observations of celestial phenomena
A small comet survived what astronomers figured would be a sure death when it...關係詞)後面字句的範圍是到哪裡? (e.g. what astronomers...death) what astronomers ...
...universe really is expanding — astronomers have decided to rewrite the ...前被認為是行星的小行星Ceres Astronomers also were asked to get rid...