题目内容
SECTION 3
Directions: Each passage in this group is followed by questions based on its content. After reading a passage, choose the best answer to each question. Answer all questions following a passage on the basis of what is stated or implied in the passage.
For the past forty years it has been known that the ammonia produced by
the rhizobia bacteria in soybean roots diffuses through membranes surrounding
bacterial cells into the soybean tissue. Interestingly, these membranes are
Line highly impermeable to organic molecules such as amino acids. Once in the plant
(5) tissue, ammonia can be incorporated into the amino acids glutamine and
glutamate, which are used to synthesize other amino acids and nitrogen-
containing molecules the plant needs, such as proteins, nucleotides and nucleic
acids.
But it has recently been discovered that the ammonium or ammonia formed
(10) by nitrogen fixation is rapidly converted into the amino acid alanine, which is
then transported out of the bacterium; thus little if any fixed nitrogen leaves the
bacteria as ammonia. While researchers remain perplexed by the means through
which alanine actually passes the membranes, they speculate that the process
may keep the newly fixed nitrogen separate from the everyday nitrogen
(15) metabolism of the bacteria themselves, thus ensuring the rapid export of most
of it to the plant.
The passage suggests which of the following about scientists' conception of the function of the amino acid alanine in the rhizobia's nitrogen fixation process？
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SECTION 2
Directions: In each of the following questions, a related pair of words or phrases is followed by five lettered pairs of words or phrases. Select the lettered pair that best expresses a relationship similar to that expressed in the original pair.
VISUAL : SIGHT ::
This division of science into two distinct cultural traditions, located in different types
Modern anthropologists hold that referential symbolism—i.e. oral speech,
writing, national flags, and flag signaling-developed later than condensation
symbolism, a highly condensed form. of substitutive behavior. for direct
Line expression that allows the release of emotional tension. Most referential
(5) symbolisms derive from unconsciously evolved symbolisms saturated with
emotional quality that have gradually acquired a purely referential character as
the linked emotion dropped out of the behavior. Thus, shaking the fist at an
imaginary enemy-condensation symbolism-becomes a dissociated and thus
referential symbol for anger when no enemy is actually intended.
(10) Once referential symbolism is established as a mere by-product of behavior,
more conscious symbols of reference are evolved by the imitation in simplified
form. of the thing signified, as in the case of pictographic writing. Referential
symbolism may also be attained by mere social agreement, as when a numbered
check is arbitrarily assigned to a man's hat. The less primary and associational
(15) the symbolism, the more dissociated from its original context, the less
emotionalized it becomes, the more it takes on the character of true reference.
If the argument in the passage is valid, a condensation symbol of performing a gesture in the presence of a specific problem would be LEAST likely to become a referential symbol for expressing dismay when
In the______era of the Regency, she alone portended the Victorian ideal to come, which was
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