本章着重讨论流体流动过程的基本原理及流体在管内的流动规律，并运用这些原理与规律去分析和计算流体的输送问题。

贴贴专栏下的单词表，来源国家地理。

In modern society, it is possible to go shopping, work and communicate via the Internet without face-to-face contact with one another. To what extent do you think this is a positive or negative development?

Today, many people put their personal and private information online (address, phone number, and credit card number) to facilitate everyday activities, such as banking, shopping, and socializing. Is this a positive or negative development?

More and more people no longer read newspaper or watch TV programs to get news. They get news about the world through the internet. Is this a positive or negative development?

Being cautious about false information online

话题下的常用词汇、短语 Expressions 翻译 world muti-polarization 世

“你只能了解你驯养的东西。”狐狸说，“人类不再有时间去了解事情了，他们总是到商店里买现在的东西。但是，却没有一家商店贩卖友谊，所以人类没

黑与白是社会的两极，也可以说是善恶的两极，而无处不在又无可逃离的灰，才是社会或者说生命的真相。这也直指电影最核心主题——命运的荒诞，生命的虚无，众生皆苦。

A recent survey shows that in many countries across the world people are generally living longer. But an increased life expectancy has many implications for the aging individuals and for the society as a whole. What are the possible effects of a longer life expectancy on individuals and the society?

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单词表制作所用代码