1。The region’s water authority is responding to the current drought by restricting residential water use. Yet reservoir levels are now at the same height they were during the drought ten years ago when no restrictions were put into effect and none proved necessary. Therefore, imposing restrictions now is clearly premature.
哪个可以削弱结论：
my answer：The population of the region is approximately 3 times greater than it was ten years ago.
right Answer: the region currently has more sources outside the drought-stricken area from which to draw water than it did ten years ago.
2。Because dinosaurs were reptiles, scientist once assumed that, like all reptiles alive today, dinosaurs were cold-blooded. The recent discovery of dinosaur fossils in the northern arctic, however, has led a number of researchers to conclude that at least some dinosaurs might have been warm-blooded, these researchers point out that only warm-blooded animals could have withstand the frigid temperatures that are characteristic of arctic winters, whereas cold-blooded animals would have frozen to death in the extreme cold
Which one of the following, if true, weakens the researchers’ argument?
My answer: the number of fossils found together indicates herds of dinosaurs so large that they would need to migrate to find a continual food supply
right Answer: the arctic dinosaur fossils were found alongside fossils of plants know for their ability to withstand extremely cold temperatures.
[此贴子已经被作者于2002-11-18 1:08:52编辑过] | 
