【正文】
還在使用哪些我們還未學(xué)過(guò)的機(jī)械來(lái)提高工作效率。pulley[puli] system Good you have any other good ideas? A B Too heavy! Help me! Do you have any good ideas? h= On my way home,I see…… B A F Good clever! Thank you ! G G G A h L B C D 斜面( inclined plane) 你想知道關(guān)于斜面的哪些問(wèn)題? ? 我想知道 ________________________? ? 我想知道 _____________________