首页
滴滴雨露
滴滴社区
美国小学
用英语学英语
在线客服
Why do acids eat through metal? Why does dishwashing liquid have a high pH? In this BrainPOP movie, Tim and Moby answer these questions.
Why do some objects sink while others float? How does a boat with an anchor inside it stay afloat while the anchor by itself would quickly sink?
Why does a fax machine have a telephone number? Tim and Moby will clue you in to this and lots of other fun fax.