Super Science走进科学

姜琴

A cactus（仙人掌） doesnt need much water. It is also good at storing（儲存） water. When it gets some water，it stores in its body. And its sharp（锋利的） spines（刺） keep animals from stealing（偷） its water.

There are stars of all sizes（尺寸） in the sky. Some look brighter（更亮的） because they are larger（更大的）. Some look brighter because they are closer（更近的） to 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 Earth.