新SAT可汗复习资料
可汗如下：
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Questions 1-11are based on the following
This passage is excerpted from Leyra Castro and Ed Wasserman, “Crows Understand Analogies,” © Scientific American 2015.
A recent research collaboration has discovered that crows exhibit strong behavioral signs of analogical reasoning—the ability to solve puzzles like “bird is to air as fish is to what?” Analogical reasoning is considered to be the pinnacle of cognition and it only develops in humans between the ages of three and four.
Why might crows be promising animals to study? Of course, crows are reputed to be clever. Aesop’s famous fable “The Crow and the Pitcher” tells of a crow solving a challenging problem: the thirsty crow drops pebbles into a pitcher with water near the bottom, thereby raising the fluid level high enough to permit the bird to drink. Such tales are charming and provocative, but science cannot rely on them.
Recent scientific research sought to corroborate this fable. It found that crows given a similar problem dropped stones into a tube containing water, but not into a tube containing sand. Crows also chose to drop solid rather than hollow objects into the water tube. It thus seems that crows do indeed understand basic cause-effect relations.
But, what happens when crows are given problems that require more abstract thinking? Before setting our sights on analogical reasoning,we might begin with a simpler abstract task. For example, sameness and differentness are key abstract ideas, because two or more items of any kind—coins, cups, caps, or cars—can be the same as or different from one another. Because sameness and differentness can be detected visually, perhaps that may provide an elegant way to study their apprehension by nonverbal animals.
To do so, we present visual stimuli on a touchscreen monitor. We reward animals with food for contacting one button when sets contain identical items and we reward animals for contacting a second button when sets contain non-identical items. Several species of birds and mammals learn this task and also transfer their learning to new stimuli, showing that they have learned an abstract concept, which extends beyond the training items.
Devising a task to study analogical thinking in animals is the next step. Here, the gist of analogy can be captured by arranging a matching task in which the relevant logical arguments are presented in the form of visual stimuli. Using letters of the alphabet for explanatory purposes, choosing test pair BB would be correct if the sample pair were AA,whereas choosing test pair EF would be correct if the sample pair were CD. Stated logically, A:A as B:B (same=same) and C:D as E:F (different:different). Critically, no items in the sample pair; so, only the analogical relation of sameness can be used to solve the task.
Now, we have found that crows too can exhibit analogical thinking. Ed Wasserman, one of the authors of this article, and his colleagues in Moscow, Anna Smirnova, Zoya Zorina, and Tanya Obozova, first trained hooded crows on several tasks in which they had to match items that were the same as one another. The crows were presented with a tray containing three cups. The middle cup was covered by a card picturing a color, a shape, or a number of items. The other two side cups were also covered by cards—one the same as and one different from the middle card. The cup under the matching card contained food, but the cup under the nonmatching card was empty. Crows quickly learned to choose the matching card and to do so more quickly from on task to the next.
Then, the critical test was given. Each card now pictured a pair of items. The middle card would display pairs AA or CD, and the two side cards would display pair BB and pair EF. The relation between one pair of items must be appreciated and then applied to a new pair of items to generate the correct answer: the BB card and in the case of AA or the EF card int the case of CD. For instance, if the middle card displayed a circle and a cross, then the correct choice would be the side card containing a square and a triangle rather than the side card containing two squares.
Not only could the crows correctly perform this task, but they did so spontaneously, from the very first presentations,without ever being trained to do so.
It seems that initial training to match identical item enabled the crows to grasp a broadly applicable concept of sameness that could apply to the novel twoitems analogy task. Such robust and uninstructed behavior represents the most convincing evidence yet of analogical reasoning in a non-primate animal.
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SAT可汗语法练习题精选内容：
Questions 1-5 are bases on the following passage.
The Complex History of the Simple Chopstick The origin of chopsticks reaches back to the Shang Dynasty of ancient China. At that time, chopsticks-which were then called ―Zhu‖-were used for cooking rather than ① to eat. Because the people-of ancient China liked to steam or boil their food, chopsticks were originally used to reach deep into boiling pots of water or oil. However, according to Chinese lore, chopsticks later evolved into an eating utensil during the Han Dynasty due to the influence of the Chinese philosopher, Confucius. Both a pacifist and vegetarian, Confucius believed that knives and other sharp utensils were inappropriate for mealtime because they reminded people of violence and warfare. Chopsticks, on the other hand, allowed people to savor their meals in a more relaxed and enjoyable setting. ②Since then, the diversity of chopstick styles and uses ③has quickly expanded. In China, for example, chopsticks are often longer and taper to a blunt end, while in Japan, chopsticks are shorter and taper to a sharp end. In addition to the length of chopsticks, the materials used to make them also vary considerably between cultures. ④ In Korea, it is also customary to use spoons for rice and chopsticks for larger, more manageable pieces of food.
As different chopstick styles have evolved over centuries, so have a number of cultural traditions and taboos. In China, for example, it is customary to transfer food between relatives as a sign of caring and respect. In Japan, on the other hand, using chopsticks to transfer food and other materials is considered taboo and is reserved solely for funeral rites. Given ⑤their importance and prominence in Asian history, it is no surprise that chopsticks have become as unique and nuanced as the cultures from which they arose.
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SAT可汗数学练习精选内容：
1.Solve for k:
k + 22 = 29
k =
Correct answer: 7 Difficulty level: 1
2.Solve for n:
-8 + n = 23
n =
Correct answer: 31 Difficulty level: 1
3.Solve for x:
x – 9 = 1
x =
Correct answer: 10 Difficulty level: 1
4.Solve for n:
18 = n - 18
n =
Correct answer: 36 Difficulty level: 1
5.Solve for k:
k + 10 = 27
k =
Correct answer: 17 Difficulty level: 1
6.Solve for t:
t + 25 = 26
t =
Correct answer: 1 Difficulty level: 1
7.Solve for k:
-30 + k = 22
k =
Correct answer: 52 Difficulty level: 1
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