Why are some stars brighter than others? 有的星星亮，有的星星暗，为什么呢？

There are stars of all sizes（尺寸）in the sky. Some lookbrighter（更亮的）because they are larger（更大的）. Somelook brighter because they are closer（更近的）to the Earth.Starlight（星光）can travel far. If a star looks small and dim（暗淡的）， it still may be（仍然可能是）a really giant（巨大的）star. It is just too far away from the Earth.