If you look up at the night sky, you can see plenty of stars. 你若抬头仰望夜空，就能看到很多的恒星。

　　Stars are large balls of burning gas in space. 恒星其实是太空中燃烧的大气球。

　　Don't you wonder how hot those stars are? 你难道不好奇那些恒星有多热么？

　　Some stars are very hot, and some stars are cool. 有的恒星是炽热的，有的恒星却是阴凉的。

　　Believe it or not, a blue or white star is hotter than a red or yellow star. 信不信由你：蓝色或白色的恒星比红色或黄色的恒星更热。