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问题 解答题

某化工企业2007年底投入100万元，购入一套污水处理设备．该设备每年的运转费用是0.5万元，此外每年都要花费一定的维护费，第一年的维护费为2万元，由于设备老化，以后每年的维护费都比上一年增加2万元．

(1)求该企业使用该设备x年的年平均污水处理费用y(万元)；

(2)为使该企业的年平均污水处理费用最低，该企业几年后需要重新更换新的污水处理设备？

答案

(1) y＝x＋＋1.5(x＞0)   (2)10年

(1)y＝，即y＝x＋＋1.5(x＞0)．

(2)由均值不等式得y＝x＋＋1.5≥2＋1.5＝21.5，

当且仅当x＝，即x＝10时取到等号，故该企业10年后需要重新更换新设备．

单项选择题

During our two months on the road, Bennett and I had a really (1) experience with a good, honest (2) and some helpful mechanics.

We were driving east on Highway 10 when our "chick engine" light came on. We limped of a(n) (3) into Las Cruces. We had a real car (4) Bennett nursed the ear into a local garage. By this time the car was missing so (5) it was shaking all over. This was the (6) time to arrive at a garage—late Friday afternoon. Service adviser Scott was busy (7) paper work and customers as we (8) our problems. (9) he was already "ten cars behind", he told us to pull the car into the garage.

Lincoln, who we later (10) was one of the two motor technicians, took (11) of our car repairing. He and Scott and some other mechanics stayed several hours after closing, (12) the car.

Early the next morning (the shop was officially closed on Saturdays), Lincoln finally located the (13) and fixed it easily within only (14)

Later Scott (15) out to us that it was our attitude that helped. "You didn’t come into the place demanding this or that. You showed an (16) of our problems on a busy Friday afternoon. Customer’s attitude means a lot. " He was right in some way, customers should show (17) and understanding to people who (18) them. (19) people were extremely busy, they found way to at least try and help when they are met with politeness.

The pleasant experience I had shows that (20) for other people can always help.

6().

A.highest 

B.easiest 

C.luckiest 

D.worst
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阅读理解与欣赏

阅读理解、分析。

　　冬天的百草园比较的无味；雪一下，可就两样了。拍雪人（将自己的全形印在雪上）和塑雪罗汉需要人们鉴赏，这是荒园，人迹罕至，所以不相宜，只好来捕鸟。薄薄的雪，是不行的；总须积雪盖了地面一两天，鸟雀们久已无处觅食的时候才好。扫开一块雪，露出地面，用一支短棒支起一面大的竹筛来，下面撒些秕谷，棒上系一条长绳，人远远地牵着，看鸟雀下来啄食，走到竹筛底下的时候，将绳子一拉，便罩住了。但所得的是麻雀居多，也有白颊的“张飞鸟”，性子很躁，养不过夜的。

　　这是闰土的父亲所传授的方法，我却不大能用。明明见它们进去了，拉了绳，跑去一看，却什么都没有，费了半天力，捉住的不过三四只。闰土的父亲是小半天便能捕获几十只，装在叉袋里叫着撞着的。我曾经问他得失的缘由，他只静静地笑道：你太性急，来不及等它走到中间去。

1．“拍雪人（将自己的全形印在雪上）和塑雪罗汉需要人们鉴赏，这是荒园，人迹罕至，所以不相宜，只好来捕鸟。”这句话传达了什么信息？    

__________________________________________

2．第一段详写了冬天在百草园的活动——捕鸟，作者分别从哪些方面写了捕鸟的情况？写这些有什么作用？   

___________________________________________

3．第一段的中心是冬天雪后捕鸟的乐趣，却先写百草园冬天的无味，这是什么写法？    

____________________________________________

 4．第二段写“我”和闰土的父亲同样的捕鸟方法，收获却不同，仔细品味词句，说说鲁迅先生为什么会在三十年后还记得“得失的缘由”？

___________________________________________

5．张飞，三国时蜀国的将领，请概括他的性格特点，并写出一个与他有关的精彩情节。   

性格：_____________________________________

情节：_____________________________________
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