Mirages(海市蜃楼) are produced by refraction(折射) of light within a layer(层), or lens

Mirages(海市蜃楼) are produced by refraction(折射) of light within a layer(层), or lens(透镜),of air. This layer of air, says meteorologist James. H. Gordon, resistsdisruption(混乱), even in a fairly strong wind.

Probablythe most typical mirage picture is one of a lake in a waterless desert. Theremay even be the appearance of waves breaking on the shore. The easiest form ofmirage to study, however, is one that has been seen by millions of people—thoseseeming strips(条状) of water on asphalt-surfaced(沥青路面的) highway go suddenly out of sight when onecomes near them.

Gordonsays Operation Long Distance as the most puzzling of mirage forms, since it ifies(使无效) a basic law of physics. The lawstates that the apparent size of an object seems to become smaller as we moveaway from it; however, this kind of mirage will carry a picture of a ship, atown, or an island a thousand miles and set it up in the sky as big as life.

Miragesmay have had an effect on history: a World War Ⅰ story, which has not beenreally verified(考证), deals with a crucial(决定性的) battle between the Turks and the British.Supposedly, the stronger Turkish army was gaining the advantage when one of itsoutposts reported British reinforcements(援兵)advancing. After a hurried conference, the Turkish forces withdrew. In realitythere were no advancing British troops(军队)—whathad been reported was a mirage showing men who were a hundred miles away.

1. Theair that carries the mirage acts as    .

A. a lens  B.a mirror

C. anabsorbent(吸收剂)  D.a camera

2. Thestrips of water are the easiest form of mirage to study because they    .

A. can beproduced in the lab

B. appearquite often

C. havebeen noted all over the world

D. do notbreak up in a light gentle wind

3. The passagestates that mirages may    .

A. bereproduced in several places at the same time

B. beenlarged to huge proportions(比例)

C. lastfor several days

D. becarried a thousand miles

4. Theauthor implies that history might have recorded a different winner in onebattle if    .

A. theTurks had described a mirage correctly

B.British troops had not been advancing

C. aTurkish outpost had not mistaken a mirage for a British advance

D.a British outpost had not reported a distant mirage

试题答案

答案：1A2B3D4C