[A] life on Earth is diversified

[B] many species of this kind were eliminated during evolution

[C] feathers evolved not for a means of transport

[D] it is very hard to have such evolution

2. 飞行的动物很少，是因为 _____。

[A] 地球上的生物是多元化的

[B] 飞行动物的许多物种在进化过程中都灭绝了

[C] 羽毛并不是为了移动的方式才进化出来的

[D] 发生这样的进化很难

答案：D　难度系数：☆☆☆☆

分析：细节题。根据第二段：Considering the diversity of life on Earth, flight is surprisingly rare. It has evolved only four times: among the insects about 300m years ago, the pterosaurs (230m), the birds (150m) and the bats (50m). That suggests it is a hard trick to pull off. 即飞行动物只进化了四次，进化是很艰难的过程，因此飞行动物的品种少。所以，答案为D。

3. The two schools of thought have different opinions on _____.

[A] the functions of feathered forearms in transition from ground to sky

[B] the location of living place before the animals' evolution to birds

[C] the development of powered flight

[D] the power provided by either gliding or flapping

3. 两派在 _____ 上有不同的观点。

[A] 长有羽毛的前臂在从地上到空中转变中的作用

[B] 这些动物进化为鸟类之前生活的地方

[C] 动力飞行的发展

[D] 力量是由滑翔或者拍动翅膀提供的

答案：C　难度系数：☆☆☆

分析：细节题。根据第三段和第四段，两派科学家在鸟类的飞行是靠滑行还是靠拍动翅膀提供的升力而形成的这一点上有分歧，因此，选项C符合题意。选项B比较具有干扰性，文章中提到，两种观点认为，这些动物在进化为鸟类之前是分别住在地面上和树上的，但这只是一个表面的原因，深层次的原因还在于选项C。

4. The conclusion of the study carried out by Dr. Glen and Dr. Bennet is that _____.

[A] powered flight developed as feathered forearms provided lift

[B] flight evolved on the ground before they descend on the trees

[C] earliest birds shared similar toes with their modern counterparts

[D] earliest flying birds evolved from feathered dinosaurs

4. Glen博士和Bennet博士在该研究中得到的结论是 _____。

[A] 长有羽毛的前臂提供了升力，从而使得动力飞行发展起来

[B] 飞行是在地上发展而来的，发生在它们落到树上之前

[C] 最早飞行的鸟类与现代鸟类的第三个脚趾相似

[D] 最早的会飞的鸟是从长羽毛的恐龙进化来的

答案：B　难度系数：☆☆☆

分析：细节题。根据第五段和第六段，他们通过研究鸟类的脚趾得出结论，鸟类一开始是在地上生活，在转移到树上生活之前就可以飞翔了，那么它们的飞翔是从地面上发展而来的。因此，答案为B。选项C具有一定的迷惑性，但是要注意的是modern counterparts的范围过于广泛，而文中说的是modern birds that spend most of their time on the ground，因此该选项错误。

5. Which one of the following statements is NOT true of opinions of Dr. Glen and Dr. Bennet?

[A] Birds realized the transition from reptile to flight by jumping.

[B] Dinosaurs are, as a matter of fact, the direct descendents of birds.

[C] Feathers evolves not for the purpose of flight.

[D] The bird's behaviour is indeed fossilized by their various shape of the third toe.

5. 关于Glen博士和Bennet博士的观点，下列哪个陈述是错误的？

[A] 鸟类依靠跳跃实现了从爬行动物到飞行动物的转变。

[B] 恐龙实际上是鸟类的直接后裔。

[C] 鸟类的羽毛不是为了飞行而进化形成的。

[D] 鸟类的行为实际上是由其第三个脚趾的不同形状决定的。

答案：B　难度系数：☆☆☆

分析：细节题。选项B，这一点不符合他们的观点，文章中的意思应该是鸟类是恐龙的直接后裔。选项A是正确的，这一点在第一段中就有所提及：But a paper in this week's Current Biology, by Christopher Glen and Michael Bennett of the University of Queensland, makes a strong case that they did it by jumping. 选项C的表述也是正确的，因为文章提到，羽毛的出现甚至是在鸟类掌握了飞行能力之后，因此不是为了这个目的。选项D的表述是正确的，文章倒数第二段提到Unfortunately, behaviour does not fossilise, so it looked as though the question might never be answered. But Dr. Glen, a palaeobiologist, and Dr. Bennett, a biomechanic, think they have worked out how to do so. 进而指出他们采用的方法就是研究鸟类的第三脚趾。因此，答案为B。





参考译文


当始祖鸟这种看上去一半是恐龙一半是鸟类的有羽毛的动物的骨架于1862年被发现，也就是《物种起源》出版的三年后，鸟类的起源成为古生物学家激烈争论的主题。有人提出，它们是兽脚亚目的恐龙（一类两足食肉恐龙，包括异龙、速龙和霸王龙）的直接后裔，这引起了一片哗然。现在，大多数研究者同意，鸟类实际上是恐龙的一个分支。但是，它们是如何从陆地转到空中生活的，在这个问题上还存在分歧。但是本周的《当今生物》上发表了昆士兰大学的Christopher Glen和Michael Bennett的一篇文章，有力地证明了鸟类正是靠跳跃实现了这种转变的。

鉴于陆地上生命的多样性，飞行动物的种类相对是极少的。飞行动物只进化过四次：3亿年前昆虫的进化，2.3亿年前的翼龙，1.5亿年前的鸟类和5千万年前的蝙蝠。这表明了进化是艰难的历程。大家普遍同意，在能够飞行之前，鸟类已先长出了羽毛。在中国东北发现的化石表明，当时拥有羽毛的动物并不能飞行，即使那些看起来完全像鸟类的也是这样。可能的情况就是，羽毛的出现或者是充当隔离层（作用和哺乳动物的皮毛一样），或者是为了好看，而自然选择又将它们转变成运动的工具。

对于接下来的进化，有两派不同看法。一派认为，鸟类的直系祖先生长在树上，该派成员认为，滑行（今天还有一些树栖动物依靠这种有控制的坠落从一棵树转移到另外一棵树上）自然会发展成为飞行。滑行自身也会发展，因为长了羽毛的前臂为其提供了升力。

另外一派的观点是，飞行是从地面活动发展而来的。该派的一些研究者认为，相当于翅膀的那个部分拍动起来产生的动力给了这些动物捕食的能力。其他的一些假设还有，长了羽毛的前臂有助于动物转向或保持平衡。

不幸的是，动作不能变成化石，因此这个问题看起来可能永远都没有答案了。但是古生物学家Glen博士和生物力学家Bennett博士认为，他们已经找出了具体的方案。他们的核心观察是现代鸟类第三个脚趾（在行走或爬行的时候，这个脚趾承载许多重量）的弯曲度因鸟类生活方式的不同而有差异。多数时间在树干上爬行的鸟类的第三个脚趾非常弯曲，而在树枝上跳来跳去的鸟类的第三个脚趾稍微弯曲，而那些主要在地上搜索食物的鸟类的第三个脚趾是最不弯曲的。

这两位研究者将这些观察结果与对中国的类鸟恐龙和类恐龙鸟的发现做了比较，他们发现，有羽毛的恐龙和最早的会飞行的鸟类的脚趾与那些大多数时间在地上活动的现代鸟类相似。换句话说，鸟类在上树生活之前就可以飞翔了。它们不是坠落的天使，而是飞起来的爬行动物。





TEXT THREE


Everyone is interested in whether different foods or nutrients affect our odds of getting diseases like cancer or of developing risk factors for those diseases, such as too much weight or high blood pressure. But there are many barriers to studying dietary change, which is why we still have no easy answers to the question of what, exactly, we should eat to be at our healthiest. It's also why you can be forgiven for often feeling whipsawed by headlines: Is coffee good or bad? What about alcohol, garlic, or chocolate?

This week researchers reported in the Journal of the American Medical Association that breast cancer survivors who cram their diets with fruits and vegetables are no more likely to escape a recurrence than women who stick to the usual five-a-day recommendation. Does that mean fruits and vegetables don't protect against cancer? No—just that in this specific group of women with breast cancer, the extra greens and additional apples didn't seem to help.

We asked researchers to explain why studies involving dietary changes are so hard to do—and what consumers should keep in mind when they read about them. Here's what the experts said:

Most diet studies take place in the real world. That means study subjects are keeping diaries of what they eat as they go rather than having their intake strictly controlled by someone else. You can give them meal advice, counseling, and how-to books up to their ears, but at the end of the day, they are on their own when it comes to what they put in their mouths. It's easier to get people to add something—like garlic, in the form of tasty sandwich spreads, or dark chocolate—than to take something away; no wonder a recent study comparing low-fat and low-carb diet plans found that almost no one was sticking to them by the end.

In studies focusing on diet, including the recent study on breast cancer recurrence, the amount of calories subjects reported eating would have caused them to lose far more weight than they actually did lose. The misreporting isn't necessarily vicious, but the inaccuracies add up. Say you're phoned about your daily intake on a day when it was someone's birthday at work and you had a slice of cake. You may not report it, thinking that a typical day wouldn't include the cake... forgetting yesterday's “special occasion” piece of pizza, and the Big Gulp of the day before. Or, despite the portion size guides you get, you characterize your bagel from the deli as a 4-ounce standard serving when a 4-ounce bagel hasn't been sighted in any major city for a decade.

“You can't put a camera in everyone's belly and see exactly what they ate,” says Christopher Gardner, a nutrition scientist at the Stanford Prevention Research Center who has recently published research on garlic and diet plans. You can get around this in some studies by taking objective measurements. Weight, for example, or if you're assessing intake of fruits and veggies, you can measure the level of pigments called carotenoids in the blood. In the breast cancer study, blood tests showed that the study subjects actually did eat more fruits and veggies (carotenoid concentration was 73 percent higher in those women after one year and 43 percent higher after four years). But objective measures can't definitively nail down whether someone is eating nutrients in certain proportions.

1. One can be forgiven for feeling whipsawed by those headlines because _____.

[A] there is no solid and convincing scientific hypothesis on these subjects

[B] the question about what the healthiest food is has no answers

[C] opinions on these subjects are quite contradictory

[D] there is no authoritative answer to these questions

2. Which one of the following statements is TRUE of the conclusion of the study on breast cancer recurrence?

[A] Women who stick to the five-a-day recommendation are less likely to have a recurrence.

[B] Women who eat extra greens and vegetables are less likely to escape a recurrence.

[C] Women could depend on fruit diet to avoid the breast cancer recurrence.

[D] Fruits and vegetables are no good to women with breast cancer.

3. From the results of the studies focusing on diet, it can be inferred that _____.

[A] the amount of calories set in diet could not help people to lose weight

[B] people are reluctant to take part in such studies

[C] it is difficult to get valuable conclusion from these studies

[D] this kind of studies is not objective enough

4. The fact that a 4-ounce bagel hasn't been sighted in any major city for a decade implies that _____.

[A] you should re-examine the standard size of the food you intake

[B] you tend to give an inaccurate report of your actual diet

[C] you fail to cooperate with the doctor by false record of your daily food

[D] you make a mistake in noting down the size of standard serving

5. The limitation of the objective measurements mentioned in the last paragraph is that _____.

[A] they could only assess the proportion of fruits and veggies study subjects have taken

[B] they could not have the subjects follow exactly the food proportion of their diet

[C] they could not identify the levels of all the nutrients in patients' blood

[D] they could not tell the exact proportions of nutrients study subjects have eaten





文章剖析


这篇文章讲述了关于饮食的一些研究中存在的问题。第一段讲述了人们对于食物和营养的困惑；第二段讲述研究表明，蔬菜和水果对于防止癌症复发没有作用；第三段和第四段讲述专家对这些问题的解释；第五段讲述对饮食的研究中存在一些人们没有进行客观报告的情况；第六段讲述更加客观的检测方法。





词汇注释


whipsaw v. 拉锯

calorie n. 卡路里

bagel n. 百吉饼

deli n. 熟食店

pigment n. 色素

carotenoid n. 类胡萝卜素





难句突破


① But there are many barriers to studying dietary change, which is why we still have no easy answers to the question of what, exactly, we should eat to be at our healthiest.

主体句式：But there are many barriers...

结构分析：这是一个复合句，which引导的定语从句用来修饰整个主句；在这个定语从句中，why引导的是表语从句，该从句中what引导的是宾语从句。

句子译文：但是要进行饮食变化的研究有太多的障碍，这就是我们为什么不能轻松而确切地告诉人们什么食物是最健康的。

② You can give them meal advice, counseling, and how-to books up to their ears, but at the end of the day, they are on their own when it comes to what they put in their mouths.

主体句式：You can give them..., but...

结构分析：这是一个并列句，后面分句中的when引导的是时间状语从句。

句子译文：你可以给他们一些用餐建议，告诉他们应该吃些什么，但是这一天里，他们往自己嘴里究竟塞了些什么东西就由不得别人了。





题目分析


1. One can be forgiven for feeling whipsawed by those headlines because _____.

[A] there is no solid and convincing scientific hypothesis on these subjects

[B] the question about what the healthiest food is has no answers

[C] opinions on these subjects are quite contradictory

[D] there is no authoritative answer to these questions

1. 人们看到那些新闻标题会觉得很迷茫，这可以理解，因为 _____。

[A] 关于这些主题的研究还没有得出可靠和可信的科学假设

[B] 关于什么食物是最健康的这个话题是没有答案的

[C] 关于这些话题的观点分歧很大

[D] 这些问题不存在权威的答案

答案：D　难度系数：☆☆☆

分析：推理题。根据第一段：But there are many barriers to studying dietary change, which is why we still have no easy answers to the question of what, exactly, we should eat to be at our healthiest. 即因为要进行饮食变化调查的障碍很多，所以在该问题上并没有一定的答案，因此，选项D最为符合题意。

2. Which one of the following statements is TRUE of the conclusion of the study on breast cancer recurrence?

[A] Women who stick to the five-a-day recommendation are less likely to have a recurrence.

[B] Women who eat extra greens and vegetables are less likely to escape a recurrence.

[C] Women could depend on fruit diet to avoid the breast cancer recurrence.

[D] Fruits and vegetables are no good to women with breast cancer.

2. 关于对乳腺癌复发的研究得出的结论，下列哪项陈述是正确的？

[A] 坚持一天五顿饭建议的妇女的复发几率要小一些。

[B] 多吃绿色蔬菜和水果的妇女并不能避免复发。

[C] 妇女可以依靠水果餐来避免乳腺癌复发。

[D] 水果和蔬菜对于患有乳腺癌的妇女没有好处。

答案：B　难度系数：☆

分析：细节题。根据第二段：...breast cancer survivors who cram their diets with fruits and vegetables are no more likely to escape a recurrence than women who stick to the usual five-a-day recommendation. 即该研究报道表明，吃大量的蔬菜和水果并不能避免乳腺癌的复发，那么选项B是正确的。选项D，虽然蔬菜和水果不能帮助妇女避免癌症复发，但是还是对她们的身体有好处的，因此这个叙述是不正确的。

3. From the results of the studies focusing on diet, it can be inferred that _____.

[A] the amount of calories set in diet could not help people to lose weight

[B] people are reluctant to take part in such studies

[C] it is difficult to get valuable conclusion from these studies

[D] this kind of studies is not objective enough

3. 从饮食研究的结果来看，可以推断出 _____。

[A] 食物中卡路里的数量并不能帮助人们减肥

[B] 人们不愿意参加这样的研究

[C] 要从这些研究中得到有价值的结论很难

[D] 这类的研究不够客观

答案：D　难度系数：☆☆☆

分析：推理题。根据第五段：...the amount of calories subjects reported eating would have caused them to lose far more weight than they actually did lose. 即这种研究的结果表明，接受实验者报告的自己摄入的卡路里的数量本来可以让他们减掉更多的体重的，这和他们自己报告的情况不够切实有关。由此可知，这样的研究不够客观。因此，答案为D。

4. The fact that a 4-ounce bagel hasn't been sighted in any major city for a decade implies that _____.

[A] you should re-examine the standard size of the food you intake

[B] you tend to give an inaccurate report of your actual diet

[C] you fail to cooperate with the doctor by false record of your daily food

[D] you make a mistake in noting down the size of standard serving

4. 已经有十年在任何一个大城市都没有出售这种4盎司的百吉饼了，这个事实说明了 _____。

[A] 你应该重新检查你摄入食物的标准量

[B] 你更容易给出与你实际饮食情况相左的报告

[C] 你错误地报告了自己每日的饮食，不能和医生很好地合作

[D] 你在记录标准饮食量时犯了一个错误

答案：B　难度系数：☆☆☆

分析：推理题。根据第五段：Or, despite the portion size guides you get, you characterize your bagel from the deli as a 4-ounce standard serving when a 4-ounce bagel hasn't been sighted in any major city for a decade. 说明，尽管吃了许多百吉饼，却报告说只吃了4盎司的那种，那么可以看出报告有误。因此，答案为B。选项C错误的原因在于，尽管报告有误，但是没有说明这就是不与医生合作。

5. The limitation of the objective measurements mentioned in the last paragraph is that _____.

[A] they could only assess the proportion of fruits and veggies study subjects have taken

[B] they could not have the subjects follow exactly the food proportion of their diet

[C] they could not identify the levels of all the nutrients in patients' blood

[D] they could not tell the exact proportions of nutrients study subjects have eaten

5. 最后一段提到的客观衡量的局限性在于 _____。

[A] 它们只能估计被研究者的水果和蔬菜的摄入量

[B] 被研究者无法严格遵循这些衡量规定的食物比例

[C] 它们分辨不了被研究者血液中所有营养物质的水平

[D] 它们提供不了被研究者已摄入营养物质的确切数量

答案：D　难度系数：☆☆☆☆

分析：细节题。根据最后一段：In the breast cancer study, blood tests showed that the study subjects actually did eat more fruits and veggies (carotenoid concentration was 73 percent higher in those women after one year and 43 percent higher after four years). But objective measures can't definitively nail down whether someone is eating nutrients in certain proportions. 可见，这种血液测量可以测出接受试验者摄入的食物和蔬菜的具体量，却不能确定人们是否摄入了一定量的营养物质。因此，答案为D。