首先我们来看一下这篇自然科普类的文章阅读和题目：
This passage is adapted from Ed Yong,“Turtles Use the Earth’s Magnetic Field as Global GPS.” ©2011 by KalmbachPublishing Co.
In 1996, a loggerhead turtle called Adelita swamacross 9,000 miles from Mexico to Japan, crossing the entire Pacific on her way. Wallace J.Nichols tracked this epic journey with asatellite tag. But Adelita herself had no such technology at her disposal.How did she steer aroute across two oceans to find her destination?
NathanPutman has the answer. By testing hatchling turtles in a special tank, he hasfound that they can use the Earth’s magnetic field as their own GlobalPositioning System (GPS). By sensing the field, they can work out both theirlatitude and longitude and head in the right direction.
Putman works in the lab of Ken Lohmann, who has beenstudying the magnetic abilities of loggerheads for over 20 years. In his lab at the University of NorthCarolina, Lohmann places hatchlings in a largewater tank surrounded by a large grid of electromagnetic coils. In 1991, hefound that the babies started in the opposite direction if he used the coils to reversethe direction of the magnetic field around them.They could usethe field as a compass to get their bearing
Later,Lohmann showed that they can also use the magnetic field to work out theirposition. For them, this is literally a matter of life or death. Hatchlings born off the sea coast ofFlorida spend their early lives inthe North Atlantic gyre, a warm current that circles between North America andAfrica. If they’re swept towards the cold waters outside the gyre, they die.Their magnetic sense keeps them safe.
Using his coil-surrounded tank, Lohmann could mimicthe magnetic field at different parts of the Earth’s surface. If he simulated the field at thenorthern edge of the gyre, the hatchlings swam southwards. If he simulated thefield at the gyre’s southern edge, the turtles swam west-northwest. Theseexperiments showed that the turtles can use theirmagnetic sense to work out their latitude their position on a north-south axis Now, Putman has shown that they can also determine their longitude—theirposition on an east-west axis
Hetweaked his magnetic tanks to simulate the fields in two positions with thesame latitude at opposite ends of the Atlantic. If the field simulated the westAtlantic near Puerto Rico, the turtles swam northeast. If the field matchedthat on the east Atlantic near the Cape Verde Islands, the turtles swam southwest.In the wild, both headings would keep them within the safe, warm embrace of theNorth Atlantic gyre.
Before now, we knew that several animal migrants,from loggerheads to reed warblers to sparrows, had some way of workingout longitude, but no oneknew how. By keeping the turtlesin the same conditions, with only the magnetic fields around them changing,Putman clearly showed that they can use these fields to find their way. In the wild, they might well also useother landmarks like the position of the sea, sun and stars
Putmanthinks that the turtles work out their position using two featuresof the Earth’s magnetic field that change over its surface They can sense the field’sinclination, or the angle at which it dips towards the surface. At the poles,this angle is roughly 90 degrees and at the equator, it’s roughly zero degrees.They can also sense its intensity, which is strongest near the poles andweakest near the Equator. Different parts of the world have unique combinationsof these two variables. Neithercorresponds directly to either latitude or longitude, but together, theyprovide a “magnetic signature” that tells the turtle where it is
Orientation of Hatchling Loggerheads Tested in Magnetic Fields
Adapted from Nathan Putman, Courtney Endres, Catherine Lohmann, and Kenneth Lohmann, “Longitude Perception and Bicoordinate Magnetic Maps in Sea Turtles.” ©2011 by Elsevier Inc.
这是一篇理科题材的文章,讲海龟的定向系统的文章,大体的意思是这个海龟能游过两个大洋达到目的地,靠什么来辨别方向呢?是磁场。叫NP的科学家通过观察小海龟在磁场受控的池子中的游泳方向，判别说他们是用磁场辨别方向的。叫KL的科学家通过控制这种池子的磁场方向，控制小海龟游泳的方向，后来又发现海龟可以利用磁场判断自己所处的位置，具体到他们可以判断自己所处的纬度。叫NP的科学家发现他们也能利用磁场在大自然中判断自己的经度。海龟们还可能依靠其他线索比如大海、太阳和星星的位置。叫NP的科学家最后总结说，海龟是利用磁场的两个特点来决定自己的位置的，一个是磁场和海平面之间的夹角，一个是磁场的强弱。任何上面的一个特点都不能准确指明他们的位置，但合起来就能提供一个磁场的位置定位。
Orientation of hatchling loggerheads tested in a magneticfield that simulates a position at the west side of the Atlantic near PuertoRico (left) and a position at the east side of the Atlantic near the Cape VerdeIslands (right). The arrow in each circle indicates the mean direction that thegroup of hatchlings swam. Data are plotted relative to geographic north 1. The passage most strongly suggests thatAdelita used which of the following to navigate her 9,000-mile journey?
(a) The current of the North Atlantic gyre
(b) Cues from electromagnetic coils designed byPutman and Lohmann
(c) The inclination and intensity of Earth’smagnetic field
(d) A simulated “magnetic signature” configuredby Lohmann
2.Whichchoice provides the best evidence for the answer to the previous question?
(a) Lines 1–2 (“In 1996...way”)
(b) Lines 23–24 (“Using...surface”)
(c) Lines 41–42 (“In the wild...stars”)
(d)Lines 49–51 (“Neither...it is”)
3.As used in line 3, “tracked” mostnearly means
(a) searched for.
(b) traveled over.
(c) followed.
(d) hunted.
4. Based on the passage, which choice bestdescribes the relationship between Putman’s and Lohmann’s research?
(a) Putman’s research contradicts Lohmann’s.
(b)Putman’s research builds on Lohmann’s.
(c) Lohmann’s research confirms Putman’s.
(d) Lohmann’s research corrects Putman’s.
5, The author refers to reed warblers andsparrows(line 37) primarilyto
(a) contrast the loggerhead turtle’s migrationpatterns with those of other species.
(b) provide examples of species that share one ofthe loggerhead turtle’s abilities.
(c) suggest that most animal species possess someability to navigate long distances.
(d) illustrate some ways in which the ability tonavigate long distances can help a species
6. It can reasonably be inferred from the passage andgraphic that if scientists adjusted the coils to reverse the magnetic fieldsimulating that in the East Atlantic (Cape Verde Islands), the hatchlings wouldmost likely swim in which direction?
(a) Northwest
(b) Northeast
(c) Southeast
(d) Southwest
新SAT中Natural Science(自然科普文章，有图表题)自然科学类篇章的主要考察范围没有发生变化，生物、地理和天文等仍是常考范围。在原有题型基础上，增加了2 题左右的图表信息题。总体难度不难，看得懂图表、读懂问题与选项，推理出问题与图表的关系即可做出。
建议：自然科学类文章较人文类文章更简单，虽总体阅读量大，但文章大意、结构较为清晰，不可大意失分，更要保证有效的阅读速度、阅读技巧。
