考生舉行GRE瀏覽測驗的備考,恰當的演習是必弗成少的,本日給考生分享的是GRE瀏覽真題200篇LEVEL2:Although the hormone adrenaline...,願望須要的考生可如下載下來然後模仿演習。
42. Although the hormone adrenaline
Although the hormone adrenaline is known to regulate memory storage, it does not pass from the blood into brain cells. We are faced with an apparent paradox: how can a hormone that does not act directly on the brain have such a large effect on brain function?
Recently, we tested the possibility that one of the hormone’s actions outside the brain might be responsible. Since one consequence of adrenaline release in an animal is an increase in blood glucose levels, we examined the effects of glucose on memory in rats. We found that glucose injected immediately after training enhances memory tested the next day. Additional evidence was provided by negative findings: drugs called adrenergic antagonists, which block peripheral adrenaline receptors, disrupted adrenaline’s ability to regulate memory but did not affect memory enhancements produced by glucose that was not stimulated by adrenaline. These results are as they should be if adrenaline affects memory modulation by increasing blood glucose levels.
17. The primary purpose of the passage is to
(A) reconcile two opposing theories
(B) compare two different explanations for a phenomenon
(C) describe experimental research that appears to support an unpopular theory
(D) present evidence that may help to resolve an apparent contradiction
(E) describe a hypothesis that has cause a controversy
18. It can be inferred from the passage that the author would most likely describe the “additional evidence” (line 12) provided by experiments with adrenergic antagonists as
(A) revolutionary
(B) disappointing
(C) incomplete
(D) unexpected
(E) corroborative
19. The passage provides information about which of the following topics?
(A) The mechanism by which glucose affects memory storage
(B) The evidence that prompted scientist to test the effects of adrenaline on memory regulation
(C) The reason that the effects of glucose on memory were tested
(D) The ways that memory storage modifies the structure of the brain
(E) The kinds of training used to test memory enhancement in rats
20. The author refers to the results of the experiment using adrenergic antagonists as “negative findings” (line 13) most likely because the adrenergic antagonists
(A) failed to disrupt adrenaline’s effect on memory
(B) did not affect glucose’s ability to enhance memory
(C) did not block adrenaline’s ability to increase blood glucose levels
(D) only partially affected adrenaline’s ability to enhance memory
(E) disrupted both adrenaline’s and glucose’s effect on memory
謎底:DECB