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Unformatted text preview: birds navigate they are able to compensate for the changing position of the Sun in the sky
○ birds innate bearings keep them oriented in a direction that is within 15 degrees of the Suns direction
○ birds' migration is triggered by natural environmental cues, such as the position of the Sun
○ birds shift their direction at a rate of 15 degrees per hour whether the Sun is visible or not
Paragraph 6 在 What about birds that migrate at night? Perhaps they navigate by the night sky. To test the idea, caged nightmigrating birds were placed on the floor of a planetarium during their migratory period. A planetarium is essentially a theater with a domelike ceiling onto which a night sky can be projected for any night of the year. When the planetarium sky matched the sky outside, the birds fluttered in the direction of their normal migration. But when the dome was rotated, the birds changed their direction to match the artificial sky. The results clearly indicated that the birds were orienting according to the stars.
10. According to paragraph 6, how did the birds navigate in the planetarium's nighttime environment? ○ By waiting for the dome to stop rotating
○ By their position on the planetarium floor
○ By orienting themselves to the stars in the artificial night sky
○ By navigating randomly until they found the correct orientation
11. Which of the following best describes the author's presentation of information in the passage? ○ A number of experiments are described to support the idea that birds use the Sun and the night sky to navigate.
○ The author uses logic to show that the biological clock in birds is inaccurate.
○ A structured argument about the importance of internal versus external cues for navigation is presented. ○ The opposing points of view about bird migration are clarified through the study of contrasting experiments.
Paragraph 7 在 There is accumulating evidence indicating that birds navigate by using a wide variety of environmental cues. Other areas under investigation include magnetism, landmarks, coastlines, sonar, and even smells. The studies are complicated by the fact that the data are sometimes contradictory and the mechanisms apparently change from time to time. Furthermore, one sensory ability may back up another.
12. The word accumulating in the passage is closest in meaning to ○ new
Paragraph 4 在 So, in another set of experiments, Kramer put identical food boxes around the cage, with food in only one of the boxes. ■The boxes were stationary, and the one containing food was always at the same point of the compass. ■However, its position with respect to the surroundings could be changed by revolving either the inner cage containing the birds or the outer walls, which served as the background. ■As long as the birds could see the Sun, no matter how their surroundings were altered, they went directly to the correct food box. ■Whether the box appeared in front of the right wall or the left wall, they showed no signs of confusion. On overcast days, however, the birds were disoriented and had trouble locating their food box. In experimenting with a...
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This note was uploaded on 09/17/2013 for the course LANGUAGE 13DL208 taught by Professor Wang during the Fall '13 term at East China Normal University.
- Fall '13