GRE试题七(2)

9. In recent years, there has been a dramatic decline in
the population of the shrike, a predatory bird that
inhabits flat land, such as farms and pastures. Some
ornithologists hypothesize that this decline is due to
the introduction of new, more effective pesticides 1 to
control the insect species on which shrikes prey 2.

The answer to which of the following questions is
NOT relevant to evaluating the ornithologists’
hypothesis?
(A) Was there a decline in the shrike population
before the new pesticides were first used?

(B) Have shrike populations declined significantly
in those habitats where the new pesticides have
not been used?
(C) Have the new pesticides more significantly
reduced the population of insect species on
which shrikes prey than did the pesticides previously 3
used?
(D) Are insects that have consumed the new pesti-
cides more toxic 4 to the shrikes that eat those
insects than were insects that consumed the
less effective pesticides?
(E) Are the new pesticides considered by most
people to be less harmful to the environment
than the old pesticides were considered to be?

10. Census 5 data for Prenland show that unmarried
Prenlandic men in their thirties outnumber unmarried
Prenlandic women in that age group by about ten to
One. Most of these men do wish to marry. Clearly,
however, unless many of them marry women who
are not Prenlandic, all but a minority will remain
unmarried.

The argument makes which of the following assump-
tions?
(A) Emigration from Preland is more common
among women than among men.
(B) A greater proportion of Prelandic women
in their thirties than of Prenlandic men of the
same age would prefer to remain unmarried.
(C) It is unlikely that many of these unmarried
Prenlandic men will marry women more than
a few years older than themselves.
(D) Prenland has a high rate of divorce.
(E) Most of the unmarried Prenlandic men are
unwilling 6 to marry women who are not
Prenlandic.

11.Certain extremely harmful bacteria found only in
sewage are difficult to detect directly. Testing for
E. coli, an easily detected and less harmful type of
bacteria, in ocean water would be a reliable way of
determining whether or not these more harmful bac-
teria are present, since ocean water contains E. Coli
only if the water is contaminated with sewage that
contains the harmful bacteria.

Which of the following, if true, most seriously
weakens the argument?
(A) There are many different strains of the E. coli
bacteria, and only some of these strains are
harmful.
(B) Some types of bacteria found in sewage are
neither disease-causing nor difficult to detect
directly.
(C) Some of the types of bacteria found in sewage
along with E. coli are not harmful to people
unless the bacteria are ingested in large quantities.
(D) E. coli dies out much more quickly than some of
the more harmful bacteria found in sewage and
then can no longer be easily detected.
(E) Some of the types of bacteria found in sewage
along with E. coli reproduce at a slower rate
than E. coli.
Questions 12-17

A bank has exactly four cashier windows, arranged in a
row and numbered consecutively 7 1through 4 from one
end of the row to the other. The bank has exactly six
cashiers: two supervisors 9 (Joan and Karim); and four
trainees 10 (Lorraine, Mark, Nora, and patrick). Throughout
a particular peak-hour period, the stationing of cashiers at
windows is restricted as follows:

There must be exactly one cashier at each window.
The cashier at window 2 must be a supervisor 8.
Lorraine must be at a window but cannot be at window 3.
If Mark is at one of the windows, Joan must be at a
window immediately adjacent to it.
The cashiers at the windows must include either Nora
or Patrick, but they cannot include both Nora and
Patrick.

12.Which of the following lists the cashiers who can be
stationed at windows 1 through 4 during this period?
1 2 3 4
(A) Joan Karim Mark Lorraine
(B) Joan Karim Nora Lorraine
(C) Karim Nora Joan Lorraine
(D) Mark Joan Lorraine Patrick
(E) Patrick Joan Nora Lorraine

13.Which of the following must be true about the

stationing of the cashiers during this period?
(A) Joan is at window 1 or at window 2.
(B) Karim is at window 2 or at window 4.
(C) Lorraine is at window 1 or window 4.
(D) Nora is at window 1 or at window 3.
(E) Patrick is at window 3 or at window 4.
sarily in that order, are stationed at immediately
adjacent windows, which of the following must be
stationed at window 4 during this period?
(A) Joan
(B) Karim
(C) Lorraine
(D) Mark
(E) Patrick