是不是这篇呀
GWD-6 Q33 to Q36:
Until recently, zoologists believed that
all species of phocids (true seals), a pin-
niped family, use a different maternal
Line strategy than do otariids (fur seals and
(5) sea lions), another pinniped family. Mother
otariids use a foraging strategy. They
acquire moderate energy stores in the
form of blubber before arriving at breeding
sites and then fast for 5 to 11 days after
(10) birth. Throughout the rest of the lactation
(milk production) period, which lasts from
4 months to 3 years depending on the
species, mother otariids alternately for-
age at sea, where they replenish their fat
(15) stores, and nurse their young at breed-
ing sites. Zoologists had assumed that
females of all phocid species, by contrast,
use a fasting strategy in which mother
phocids, having accumulated large energy
(20) stores before they arrive at breeding sites,
fast throughout the entire lactation period,
which lasts from 4 to 50 days depending on
the species. However, recent studies on
harbor seals, a phocid species, found that
(25) lactating females commenced foraging
approximately 6 days after giving birth and
on average made 7 foraging trips during
the remainder of their 24-day lactation
period.
(30) The maternal strategy evolved by
harbor seals may have to do with their
small size and the large proportion of their
fat stores depleted in lactation. Harbor
seals are small compared with other phocid
(35) species such as grey seals, northern ele-
phant seals, and hooded seals, all of which
are known to fast for the entire lactation
period. Studies show that mother seals of
these species use respectively 84 percent,
(40) 58 percent, and 33 percent of their fat
stores during lactation. By comparison,
harbor seals use 80 percent of their fat
stores in just the first 19 days of lactation,
even though they occasionally feed during
(45) this period. Since such a large proportion
of their fat stores is exhausted despite
feeding, mother harbor seals clearly cannot
support all of lactation using only energy
stored before giving birth. Though smaller
(50) than many other phocids, harbor seals are
similar in size to most otariids. In addition,
there is already some evidence suggesting
that the ringed seal, a phocid species that
is similar in size to the harbor seal, may
also use a maternal foraging strategy.
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Q33:
It can be inferred from the passage that the females of all phocid species differ from the females of all otariid species in that the female phocids
have shorter lactation periods consume more food during lactation consume a higher proportion of fat stores forage for food occasionally during their lactation periods deplete a smaller percentage of their fat stores during their lactation periods Answer:
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Q34:
The primary purpose of the passage is to
present evidence that several phocid species use the maternal fasting strategy explain why the maternal strategy typically used by phocids is different from the maternal strategy used by otariids argue that zoologists’ current understanding of harbor seals’ maternal strategy is incorrect describe an unexpected behavior observed in harbor seals and propose an explanation that may account for that behavior describe evidence concerning the maternal strategy of the harbor seal and suggest that the harbor seal belongs to the otariid rather than to the phocid family Answer:
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Q35:
According to the passage, until recently zoologists believed which of the following about all phocid mothers?
Their fasting periods after giving birth were typically shorter than those of otariids. Their lactation periods were generally as long as those of comparably sized otariids. They acquired only moderate energy stores in the form of blubber before arriving at breeding sites. They depleted less than a third of their stored body fat during lactation. The replenished their fat stores only after their lactation period ended. Answer:
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Q36:
The author of the passage mentions ringed seals most probably in order to
provide an example of a phocid species that fasts throughout its entire lactation period provide an example of a phocid species whose maternal strategy is typical of phocid species provide an example of a phocid species that may deplete an even higher proportion of its fat stores during lactation than harbor seals do support the assertion that harbor seals are smaller than many other phocids support the assertion that harbor seals’ maternal strategy may be related to their small size Answer:
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发表于 2006-8-25 09:09:00
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