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Until recently, zoologists believed that 动物学家一直相信所有p all species of phocids (true seals), a pin- 型海豹的母亲策略和o型 nipped family, use a different maternal 是不同的。 Line strategy than do otariids (fur seals and (5) sea lions), another pinniped family. Mother O豹妈妈运用觅食策略。 otariids
use a foraging strategy. They 它们到达饲养地前先以鲸 acquire moderate energy stores in the 脂形式储存能量，产仔后 form of blubber before arriving at breeding 禁食5到11天。 sites and then fast for 5 to 11 days after (10) birth. Throughout the rest of the lactation 在后来4个月到3年的 (milk production) period, which lasts from 泌乳期里，它们都会在海 4 months to 3 years depending on the 里觅食，重获力量养儿。 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 动物学家以为P豹运用禁 females of all phocids species,
by contrast, 食策略，即妈妈在4到50 use a fasting strategy in which mother 天的泌乳期内戒食。 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 但是近期对H豹-一种P harbor seals, a phocids species, found that 类豹的研究发现，泌乳雌 (25) lactating females commenced foraging 性产仔后约6天开始觅食， approximately 6 days after giving birth and 在24天的泌乳期内平均觅 on average made 7 foraging trips during 食7次。 the remainder of their 24-day lactation period. (30) The maternal strategy evolved by H豹的母亲策略与其体积 harbor seals may have to do with their 小消耗大是有关的。 small size and the large proportion of their fat stores depleted in lactation. Harbor H豹与其它P类豹如灰海 seals are small compared with other phocids 豹相比体型更小，灰海豹 (35) species such as grey seals, all of which 整个泌乳期就戒食。 are known to fast for the entire lactation period. Studies show that mother seals of 其它P类豹在泌乳期 these species use respectively 84 percent, 内分别消耗84%,58%和 58 percent, and 33 percent of their fat 33%的脂肪。 (40) stores during lactation. By comparison, 相比之下，H豹在泌乳期 harbor seals use 80 percent of their fat 的前19天就消耗了80% stores in just the first 19 days of lactation, 的脂肪。 even though they occasionally feed during this period. Since such a large proportion 所以它们要去觅食。 (45) 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 H豹虽然比其他P豹小， than many other phocids, harbor seals are 但与O豹的体型类似。 (50) similar in size to most otariids. In addition, 另外证据显示体型类似 there is already some evidence suggesting H豹的P型环斑海豹也 that the ringed seal, a phocids species that 使用觅食策略。 is similar in size to the harbor seal, may also use a maternal foraging strategy. 文章两处用到了对比：phocids和otariids；harbor seals和other phocids T-7-33 It can be inferred from the passage that the females of all phocids 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
Throughout the rest of the lactation (milk production) period, which lasts from 4 months to 3 years；the entire lactation period, which lasts from 4 to 50 days
T-7-34 The primary purpose of the passage is to - present evidence that several phocids 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 the 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 phocids family
T-7-35 According to the passage, until recently zoologists believed which of the following about all phocids 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.
是问zoologists以前的观点。
T-7-36 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
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发表于 2008-11-12 19:14:00
