Many people are aware of the beauty of a solar eclipse , but are surprised to le

Many people are aware of the beauty of a solar eclipse(日食), but are surprised to learn that lunareclipses are often just as impressive. While total solar eclipse lasts only fora few minutes and can be seen only in a small area of a few kilometers, totallunar eclipse can last for several hours and can be seen over much of theplanet. In fact, the beauty and stability of lunar eclipses make them afavorite of both amateur and professional photographers.

    Lunar eclipses generally occur twoor three times a year, and are possible only when the Moon is full. When we seethe Moon, we are actually seeing sunlight reflected off the surface of the MoonWhen the Earth is positioned in between the Moon and the Sun, however, theEarth's shadow falls on the Moon, and a lunar eclipse occurs.

     The type of lunar eclipse -total, partial, or penumbral (半影) - that occurs dependsboth on how much of the Moon passes through the Earth's shadow and through whichpart of the shadow it passes. A penumbral eclipse occurs when the Moon passes throughthe Earth's outer shadow. This type of eclipse is brief and frequently goes unobservedby all but astronomers. By contrast, total and partial eclipses occur when allor part, respectively, of the Moon passes through the umbra（本影） shadow of the Earth. These eclipses are quite easy tosee and are widely observed.

     Unlike solar eclipses, lunareclipses are safe to watch. Solar radiation that occurs during an eclipse ofthe Sun can cause a form of burns of one's eyes known as eclipse blindness. Infact, the only way to safely view a solar eclipse is by using speciallydesigned equipment. However, since the Moon's light is reflected sunlight, itis completely safe to watch a lunar eclipse without any special equipment,although a pair of binoculars can certainly help the viewer appreciate thebeauty of this phenomenon

1.The underlined word "stability "most probably means_______.

A. strength      B.position             C. steadiness           D.visibility

2.According to the passage, a partial lunar eclipseoccurs________.

A. when the Moon passes between the Sun and the Earth

B. when all of the Moon passes through the Earth'sumbra shadow

C. when only a part of the Moon passes through the Earth'souter shadow

D. when only a part of the Moon passes through theEarth's umbra shadow

3.The passage implies that penumbral eclipsesare________.

A. longer-lasting than most solar eclipses

B. more common than partial or full lunar eclipse

C. the result of the shadow cast by the Moon onto theEarth

D. more difficult to observe than other types of lunareclipse

4.According to the passage, it is safe to watch alunar eclipse, unlike a solar eclipse, because ________.

A. moonlight is less strong than sunlight

B. a lunar eclipse is briefer than a solar eclipse

C. a lunar eclipse lasts much longer than a solareclipse

D. special equipment can be employed to view a lunareclipse

试题答案

【答案】

1.C

2.D

3.D

4.A

【解析】

试题