【英语时差8,16】为何食盐不黏在一起？

 Our last program talked about table salt, technically¹ called sodium² chloride, which is available in iodized form–that means that it includes a small amount of potassium iodide or sodium iodide added to the sodium chloride. Iodized salt is intended to supply us with the chemical element iodine³, an essential nutrient⁴. Iodized salt has been available in the United States since 1924. Sticky Situation But a table-salt additive⁵ even more common than iodine is some anti-caking agent, to keep the salt crystals from sticking together as they absorb moisture from the air. Salt crystals are made of sodium and chlorine atoms linked together like Tinkertoys to form a three-dimensional framework. Because the atoms are evenly spaced and the connections between atoms are at right angles, sodium chloride crystals take the form of cubes. Those cubes can pack closely together, like children’s blocks. As those closely-packed cubes absorb water from the air, they partially⁶ dissolve and fuse together.

1 technically   

adv.专门地，技术上地

参考例句：

• Technically it is the most advanced equipment ever.从技术上说，这是最先进的设备。
• The tomato is technically a fruit,although it is eaten as a vegetable.严格地说，西红柿是一种水果，尽管它是当作蔬菜吃的。

2 sodium   

n.（化）钠

参考例句：

• Out over the town the sodium lights were lit.在外面，全城的钠光灯都亮了。
• Common salt is a compound of sodium and chlorine.食盐是钠和氯的复合物。

3 iodine   

n.碘，碘酒

参考例句：

• The doctor painted iodine on the cut.医生在伤口上涂点碘酒。
• Iodine tends to localize in the thyroid.碘容易集于甲状腺。

4 nutrient   

adj.营养的，滋养的；n.营养物，营养品

参考例句：

• Magnesium is the nutrient element in plant growth.镁是植物生长的营养要素。
• The roots transmit moisture and nutrient to the trunk and branches.根将水分和养料输送到干和枝。

5 additive   

adj.附加的；n.添加剂

参考例句：

• Colour is often an additive in foods.颜料经常是各种食物中的添加物。
• Strict safety tests are carried out on food additives.对食品添加剂进行了严格的安全检测。

6 partially   

adv.部分地，从某些方面讲

参考例句：

• The door was partially concealed by the drapes.门有一部分被门帘遮住了。
• The police managed to restore calm and the curfew was partially lifted.警方设法恢复了平静，宵禁部分解除。