TTGWD2-Q17找不到解释

dxychristy

Parland’s alligator population has been declining in recent years, primarily because of hunting.  Alligators prey heavily on a species of freshwater fish that is highly valued as food by Parlanders, who had hoped that the decline in the alligator population would lead to an increase in the numbers of these fish available for human consumption.  Yet the population of this fish species has also declined, even though the annual number caught for human consumption has not increased.

Which of the following, if true, most helps to explain the decline in the population of the fish species?

A.     The decline in the alligator population has meant that fishers can work in some parts of lakes and rivers that were formerly too dangerous.

B.     Over the last few years, Parland’s commercial fishing enterprises have increased the number of fishing boats they use.

C.     Many Parlanders who hunt alligators do so because of the high market price of alligator skins, not because of the threat alligators pose to the fish population.

D.     During Parland’s dry season, holes dug by alligators remain filled with water long enough to provide a safe place for the eggs of this fish species to hatch.

IE   In several neighboring countries through which Parland’s rivers also flow, alligators are at risk of extinction as a result of extensive hunting

为什么是D

Q22: TTGWD2-Q17:

Tanco, a leather manufacturer, uses large quantities of common salt to preserve animal hides.  New environmental regulations have significantly increased the cost of disposing of salt water that results from this use, and, in consequence, Tanco is considering a plan to use potassium chloride in place of common salt.  Research has shown that Tanco could reprocess the by-product of potassium chloride use to yield a crop fertilizer, leaving a relatively small volume of waste for disposal.

 

In determining the impact on company profits of using potassium chloride in place of common salt, it would be important for Tanco to research all of the following EXCEPT:重點在the impact on company profits

 

1. What difference, if any, is there between the cost of the common salt needed to preserve a given quantity of animal hides and the cost of the potassium chloride needed to preserve the same quantity of hides?
2. To what extent is the equipment involved in preserving animal hides using common salt suitable for preserving animal hides using potassium chloride?
3. What environmental regulations, if any, constrain the disposal of the waste generated in reprocessing the by-product of potassium chloride?
4. How closely does leather that results when common salt is used to preserve hides resemble that which results when potassium chloride is used?
5.  Are the chemical properties that make potassium chloride an effective means for preserving animal hides the same as those that make common salt an effective means for doing so

WHY E

[此贴子已经被作者于2007-8-1 2:04:42编辑过]