宝春

各位同学们，为了督促帮助大家持续提升英语能力，培君老师们特意给大家准备了托福每日一包。每天覆盖听说读写内容，坚持完成两周以上，就能见到自己的英语能力不断上涨哟。

1.听写包 答案：

For instance, how many of you play a brass instrument, like a trumpet or a trombone?

Well, brass is an alloy of copper and zinc, if your trombone was made of pure copper or pure zinc, it wouldn’t sound nearly as beautiful as a brass trombone.
Another alloy, a combination of copper and nickel, resists corrosion.
It does not rust, even with prolonged exposure to water.
But what about the Statue of Liberty in New York Harbor?
It’s made of pure copper, but it turned green, isn’t that a sign of corrosion?
Indirectly. If copper’s exposed to damp air, its color changes from reddish orange to reddish brown.
But in time, a green film, called a patina, forms and the patina actually serves to halt any further corrosion.
It is one reason that ship hulls are made of copper-nickel alloys, these alloys are also hard for the barnacles to stick to.
If these little shellfish adhere to the hull of a ship, it produces drag, slowing the vessel down.
Copper’s also a key material used in solar heating units and in water desalination plants, which will play increasingly important roles in society.
Bottom line: if you are a copper miner, you won’t lose any sleep should the penny get...if you’ll excuse the expression, pinched out of existence.
举个例子来说，你们中玩铜管乐器的人多不多，比如喇叭或者长号？
铜管乐器是铜和锌的合金，如果你的长号是用纯铜或者纯锌制作的，它演奏起来就不如铜锌合金的听起来美妙。
另一种合金是铜镍合金，抗腐蚀性很强。
即使长时间浸在水中，它也不会生锈。
但是纽约港的自由女神像呢？
它是由纯铜制作的，但是却变成了绿色，那不是腐蚀的迹象吗？
间接地。如果铜暴露在湿润的空气中，它的颜色会从红褐色变成红棕色。
但是后来会形成一层叫做铜绿的绿色薄膜，铜绿实际上起着阻止进一步腐蚀的作用。
船体用通镍合金制作的原因之一就是这个，甲壳动物还很难粘附在这些合金上。
如果这些小型甲壳动物粘在了船体上，就会产生拖力，减慢船速。
铜还是太阳能加热装置和水体淡化工厂使用的一种关键材料，它在社会中的作用将越来越重要。
概括来说：如果你是铜矿工人，万一便士被......请原谅我的用语，被斩杀了，你也不会担心得睡不着觉。

2.阅读包答案：

每个学期，客座教授要负责做5次演讲，举办2次研讨会，并对本系的研究工作作不时的监督。

3.写作包答案：

China has a vast land and a large population. Even though the Chinese language is spoken all over the country, people in different areas speak it in different ways, which are called dialects. Generally called local languages, dialects are branches of the Chinese language in different regions, and are only used in certain areas. Dialects of the Chinese language are very complicated. They differ from each other in three aspects: pronunciation, vocabulary and grammar. And the difference in pronunciation is the most outstanding. Over 2,000 years ago, Chinese people realized that a common language should be used in social activities. Compared with dialects，mandarin can be understood by all people. It is beneficial to information transmission and cultural exchange between ethnic groups and people in different places.