French astronomer arago once said, "If we don't see objects falling all the time, gravity will be a very strange phenomenon for us."
Astronomer carl sagan once said: "Everyone is a scientist when he is young, because every child, like a scientist, is full of curiosity and awe of the wonders of nature."
Zhang Heng, a great astronomer in the Han Dynasty, once said, "Life is diligent, what is there without seeking?"
Astronomer Zhang Heng once said: "If you don't respect your position and morality, you are not ashamed of being uncooperative and ignorant."