在我国实施的“西气东输”工程中，西部地区的天然气被输送到缺乏_爱下问搜题

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问题填空题

在我国实施的“西气东输”工程中，西部地区的天然气被输送到缺乏能源的东部地区．天然气与煤相比，从热学角度分析它突出的优点是______________；从环保角度分析它突出的优点是______________．（天然气、煤的热值分别为1.14×10⁸J/kg、3×10⁷J/kg）

答案

分析：（1）从热学角度分析，相等质量的物质，热值大的放热就多．

（2）从环保角度分析，天然气燃烧污染小，煤燃烧还要放出别的废气污染就大．

解：（1）从热学角度分析，天然气的热值大，相等质量的物质，热值大的放热就多．

（2）从环保角度分析，天然气燃烧污染小，而煤燃烧不仅放出二氧化碳，还要放出别的废气．

故答案是：热值大，污染小．

点评：从热学角度和环保角度两方面考查了学生学以致用的能力．注意对学生实际生活中物理知识的运用．

问答题

经济订货批量

完形填空

Years ago, if a teenager had some problems in his life, he might go home and write in his diary; now, a teenager with 26 problems might go onto the Internet and write about them in a blog（博客）．In many ways, a diary and a blog are very 27 ．But what makes blogging different from writing in a（n） 28 diary?
The biggest difference is that a blog is much more   29  than a diary. Usually, a teenager treats his diary like a book full of   30  that he does not want to   31 with others.
It’s interesting that someone who writes in a blog   32 a diary will probably write nearly the same information.
I have a little sister, and sometimes I go online to read her   33 . She writes about things like waking up early for swimming practice and not studying enough for her chemistry test. 34 I was her age, I wrote about the same things, but   35 in my dairy. Then, after I had finished writing, I would hide my diary in a secret place because I was 36 that my sister might read it.
The biggest   37  with blogging is that anyone can read what you write. If I was angry with a friend during high school and wrote something   38 about him in my diary, he would never know. 39 , if my sister ever wrote something bad about a friend, that friend might   40 her blog and get angry.
There are also   41  to blogging, of course. If I was feeling sad one day and wrote in my diary, “ Nobody cares about me”, because no one would   42 about it. However, if my sister wrote the same sentence in her blog, her best friends would quickly   43  and tell her how much they 44  her. Blogs help people   45 in contact with their friends and know what the people around them are doing.

B．interesting

D．traditional

C．shortcomings