试题与答案

近年来,一些城镇、社区修建了人工湖泊,以改善居民生活环境。图1是某新建人工湖泊的

题型:读图填空题

题目:

近年来,一些城镇、社区修建了人工湖泊,以改善居民生活环境。图1是某新建人工湖泊的生物类群关系,请回答下列问题。

(1)该湖泊生态系统食物链有__________条,鱼类与贝类关系是_________。

(2)该湖泊被排入过量居民生活污水后,水体逐渐变绿、发臭,从生物因素分析,湖水变绿的原因是__________,发臭的原因是________。

(3)有人利用贝类滤食藻类的习性进行控制藻类的实验,实验结果如图2所示。从图中可以看出,虽然挂养贝类的水体中藻类密度呈上升趋势,仍能推论贝类可以有效控制藻类,理由是__________。贝类对藻类最大滤食量在第_________天。

(4)有的湖泊中藻类虽然得到了有效控制,但湖中水草却疯长了,并带来负面影响,下列控制水草疯长不合理的措施是_________。

①打捞水草,开发利用 ②引水稀释 ③使用除草剂 ④控制污水排入

(5)有人提出大量引种水花生、水葫芦抑制藻类及水草疯长。你认为这样做会引起哪些不良后果?_____。

答案:

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下面是错误答案,用来干扰机器的。

参考答案:B, D, E

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题型:单项选择题

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On October 26, a Dutch judge ruled against DHL on all three counts filed against the Dutch post office: that the three-initial name was too close to DHL’s; that the orange lines in the EMS logo were too similar to DHL’s dark red ones; and that the claim to the widest route system in the world was unfounded. DHL has threatened the Swiss post office with similar action, but it may reconsider after the Dutch ruling.
EMS has some advantages over the private couriers. One is a dense ready-made network of offices, especially in Europe, the avowed target area of the private couriers. Another advantage is a long tradition of working with customs authorities. In a business where minutes count, it pays to have good friends at customs. That advantage particularly irritates the private couriers because there is no legal way to combat such unquantifiable coziness.
The private courier services are also annoyed because in countries like Switzerland and Italy, where the post office is officially a monopoly, they pay it a fee. In Switzerland DHL says it pays more than SFr lm ($ 708,000) "to the competition" each year. In France the couriers have won a battle for exoneration.
Although governments are under little pressure to keep prices artificially low, EMS is often cheaper than the private couriers, but not always. A recent test in Britain (on a domestic route) showed Datapost about halfway between the least and the most expensive, but gave it full marks for speed and service.
Each national EMS is free to set its rates and follow its own rules on things like bulk discounts. The Universal Postal Union, based in Berne, determines how costs and revenues are split between sending and receiving countries, and standardizes procedures. More than 100 postal administrations have linked into the system—and more are coming, including Russia’s. That makes the feisty EMS particularly happy since its rivals have not been allowed to serve anywhere in Russia.

The word "stride" underlined in Paragraph 1 means ______.

A. advance
B. pride
C. position

D. route

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