How does the environment change along the Colordo River?
其實(shí)這篇說難也不難，但由于一直在糾發(fā)音，造成讀這本很疲勞
關(guān)于河流經(jīng)過的四個(gè)區(qū)域，都沒有仔細(xì)去分析
應(yīng)該復(fù)讀比較好。
You have learned how water can make sand act differently than normal. Now, see how water changes cornstarch! Pour one cup of cornstarch into a bowl. Take notes on how it feels. Next, pour one cup of water into the bowl, stirring slowly as y...
As plants make food, they also make a gas called oxygen. Plants give off oxygen through their leaves. All animals need this oxygen to live and breathe. Plants also give off water vapor through their l...
2010
