问题 单项选择题

据报道,某国科学家在一块60万年前来到地球的火星陨石上发现了有机生物的痕迹,因为该陨石由二氧化碳化合物构成,该化合物产生于甲烷,而甲烷可以是微生物受到高压和高温作用时产生的。由此可以推断火星上曾经有过生物,甚至可能有过象人一样的高级生物。以下条件除了哪项外,都对上文的结论提出质疑

A.火星陨石在地球上的60万年间可能产生了很多的化学变化,要界定其中哪些物质仍完全保留着在火星上的性质不是那么容易的。

B. 60万年的时间与宇宙的年龄相比是微不足道的,但在这一期间的生物进化的历史可以是丰富多彩的。

C.微生物受到高压和高温作用时可以产生甲烷,但甲烷是否可以由其他方法产生是有待探讨的一个问题。

D.由微生物进化到人类需要足够的时间和合适的条件,其复杂性及其中的一些偶然性可能是现在的人们难以想象的。

答案

参考答案:C

解析:只有C项对题干的结论提出了质疑.

单项选择题
阅读理解

阅读理解。

     Death Valley is one of the most famous deserts in the United States, covering a wide area with its alkali

sand. Almost 20 percent of this area is well below sea level, and Badwater, a salt water pool, is about 280

feet below sea level and the lowest point in the United States.

     Long ago the Panamint Indians called this place “Tomesha”- the land of fire. Death Valley's present

name dates back to 1849, when a group of miners coming across from Nevada became lost in its

unpleasantness and hugeness and their adventure turned out to be a sad story. Today Death Valley has

been declared a National Monument and is crossed by several well-marked roads where good services can

be found easily. Luckily the change created by human settlement has hardly ruined the special beauty of this

place.

     Here nature created a lot of surprising scenes, almost like the sights on the moon, ever-changing as the

frequent wind moves the sand about, showing the most unusual colors. One of the most astonishing and

colorful parts of Death Valley is the Devil's Golf Course, where it seems hard for one to tell reality from

dreams. Sand sculptures stand-on a frightening ground, as evening shadows move and lengthen.

1.The name “Death valley” comes from _____.

A. an Indian name

B. the death of the miners

C. the local people

D. a National Monument

2. From the passage we can learn that _____.

A. no one had ever known the desert before the miners

B. it's still not easy to travel across the desert

C. people can find gas-stations, cafes and hotels in the desert

D. people have changed the natural sight of the desert

3. The Devil's Golf Course is famous for _____.

A. the terrible sights

B. the moon-like sights

C. the dream-like sights

D. the ever-changing sights

4. From the passage we can see that the writer _____ the Death Valley .

A. appreciates

B. is fearful of

C. dislikes

D. is tired of