Question

Scientists have found what look like caves on Mars(火星), and say they could be protecting life from the planet’s terrible environment.

     The first caves discovered beyond the Earth appear as seven mysterious black dots on the pictures sent back by NASA’s Mars Odyssey orbiter. Each as large as a football field, they may be openings into natural caves below the Martian surface.

    “If there is life on Mars, there is a good chance you’d find it in caves,” said Jut Wynne, one of the researchers who noticed the features while working on a US Geological Survey Mars Cave Detection Program.

    Jonathan Clarke, a geologist with the Mars Society of Australia, yesterday described the discovery as exciting.

    One photo taken at night by an infrared imager(紅外線成像器) showed one hole to be unusually warm, suggesting hot air trapped during the day is flowing out.

    “I said: ‘Wow, that’s a cave’” Dr. Clarke said excitedly. “People have been looking for these for a long time; now we have found them.”

    He agreed such caves would be perfect places to hunt for life escaping from the bitterly cold, radiation-soaked(充滿輻射的), dry surface.

     “Tiny drops of water could collect inside,” he said. “If there are gases coming out, they could provide energy for a whole range of bacteria. A cave is also a protection from radiation; the surface of Mars is exposed to high levels of space radiation.”

     The caves probably formed when tube-shaped lave flows(管狀巖漿流) spread across the planet long ago. The outside of the tubes cooled, forming solid walls, while something hotter inside allowed the remaining have to flow out, forming caves. 

What does the passage mainly talk about?

A. How the caves were formed on Mars.             B. How scientists found these caves on Mars.

C. Caves on Mars may be full of hot air or a sign of life.

D. Scientists have completely recognized the surface of Mars.

We can learn from the passage that           .

A. water has already been found on Mars            B. the scientists found all the caves at night

C. it is certain that there is life in these caves

D. the surface of Mars is bitterly cold, radiation-soaked and dry

According to the passage, Dr. Clarke was so excited because        .

A. such caves could provide energy for life         B. they had finally found the caves on Mars

C. such caves would be perfect places to hunt for life

D. scientists had long been looking for these caves

Necessary conditions for life on Mars mentioned in the passage may include        .

A. lava and energy                                           B. water and radiation from space

C. gases and lava                                              D. water and protection from radiation

Answer 1

【小題1】C

【小題2】D

【小題3】B

【小題4】D

解析:

【小題1】這是一道主旨題。本文主要介紹了科學家在火星上發(fā)現(xiàn)一些坑洞，這些坑洞可以聚集熱空氣和水分，使生命出現(xiàn)變得可能。本文也描述了這些坑洞發(fā)現(xiàn)的過程和形成原因，但都不是主要描述的內(nèi)容，所以A項和B項不全面。

【小題2】這是一道判斷題。根據(jù)倒數(shù)第三段“He agreed such caves would be perfect places to hunt for life escaping from the bitterly cold, radiation-soaked, dry surface.”可以判斷出火星表面是個極端寒冷、充滿輻射、干燥的地方。A、C選項都是文中的推測，并沒有得出明確的結(jié)論。

【小題3】這是一道推斷題。根據(jù)第六段Dr.Clarke的表述“People have been looking for these for a long time；now we have found them.”可知Clarke教授的喜悅是因為人們找這些坑洞很長時間了，現(xiàn)在終于找到了。

【小題4】這是一道歸納題。根據(jù)坑洞中可能出現(xiàn)生命以及倒數(shù)第二段“Tiny drops of water could collect inside,”和“A cave is also a protection from radiation”可以歸納出生命產(chǎn)生需要水和避免輻射。