【英语时差8,16】糖为什么会溶解？

 Did you ever wonder why sugar dissolves in a cup of coffee? Why not have the sugar just float in the middle of the cup, without dissipating into the coffee? It’s because of the way water molecules² interact with molecules in other substances. A water molecule¹ has powerful magnetic properties, because of the two positively³ charged hydrogen atoms stuck to a negatively charged oxygen atom. A water molecule can actually break apart the bonds that hold together sugar molecules and insert itself in between them. This is what’s happening on a molecular⁴ level when you see the sugar cube getting wet and crumbling⁵ apart. Water molecules are busily inserting themselves between sugar molecules. Eventually they come between all the sugar molecules, dissolving the sugar cube.

1 molecule   

n.分子，克分子

参考例句：

• A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
• This gives us the structural formula of the molecule.这种方式给出了分子的结构式。

2 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

3 positively   

adv.明确地，断然，坚决地；实在，确实

参考例句：

• She was positively glowing with happiness.她满脸幸福。
• The weather was positively poisonous.这天气着实讨厌。

4 molecular   

adj.分子的；克分子的

参考例句：

• The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
• For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。

5 crumbling   

adj.摇摇欲坠的

参考例句：

• an old house with crumbling plaster and a leaking roof 一所灰泥剥落、屋顶漏水的老房子
• The boat was tied up alongside a crumbling limestone jetty. 这条船停泊在一个摇摇欲坠的石灰岩码头边。