【求助】T-4-26;T-7-35

wenchang

Until recently, zoologists believed that all species of phocids (true seals), a pin-nipped family, use a different maternal strategy than do otariids (fur seals and     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 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 forage at sea, where they replenish their fat stores, and nurse their young at breeding sites. Zoologists had assumed that females of all phocids species, by contrast, use a fasting strategy in which mother phocids, having accumulated large energy 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 phocids species, found that 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.
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 phocids species such as grey 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, 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 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 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 phocids species that is similar in size to the harbor seal, may also use a maternal foraging strategy.


According to the passage, until recently zoologists believed which of the following about all phocids mothers?
A.    Their fasting periods after giving birth were typically shorter than those of otariids.
B.    Their lactation periods were generally as long as those of comparably sized otariids.
C.    They acquired only moderate energy stores in the form of blubber before arriving at breeding sites.
D.    They depleted less than a third of their stored body fat during lactation.
E.    The replenished their fat stores only after their lactation period ended.

答案是E，做完了感觉E确实是对的，不过A似乎也是对的啊？望NN多多指导

wenchang

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若雪

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easy4meeeeee

1. They (O seal) acquire moderate energy stores in the form of blubber before arriving at breeding sites and then fast for 5 to 11 days after birth.
2. Zoologists had assumed that females of all phocids species, by contrast, use a fasting strategy in which mother phocids, having accumulated large energy stores before they arrive at breeding sites, fast throughout the entire lactation period, which lasts from 4 to 50 days depending on the species.
这题有点意思

Stegosaurus

我觉得这个题的意思是说“直到最近，动物学家们才认为······”，说明这问的是目前的看法，但E明显说的是过去的看法，因为Harbor seal就把这个观点给推翻了啊！

laihong

A 里面的 A.    Their fasting periods after giving birth were typically shorter than those of otariids.来自于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 birth.

而里面的 their, 即题目中的phocid
However, recent studies on harbor seals, a phocids species, found that 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.

typically 表示通常的意思， 6 和5-11 没法进行通常比较

DeliciaAn

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