Question

    The exact work of ancient astronomers has led to a modern observation --- our days are longer than they used to be. Not that you’d noticed: The new research in the Proceedings of the Royal Society A shows that it takes the Earth a tiny bit longer these days to complete a single rotation (转动) than it did millions of years ago. It’s the kind of stuff that’s measured in milliseconds per century, but those milliseconds add up. Over the last thousands of years, they’d totaled several hours, which the Los Angeles Times puts this way, “If humanity had been measuring time with an atomic clock that started running back in 700 BC, today that clock would read 7 p.m. when the sun is directly overhead rather than noon. The atomic clock won’t lose a second for 15 billion years.” Maybe more remarkable is that the work is the result of a tireless 40-year research into ancient timekeeping records dating back 2,700 years.

Scientists led by Richard Stephenson of the UK’s Durham University have been studying Babylonian clay tablets, Chinese observations made through the use of water clocks, and Arab astronomical records that tracked solar and lunar eclipses(日/月食). “The most astonishing thing about this study is the fact that we have this information at all,” said a geographer not involved in the study. Researchers are still hoping to find observations from the Incas and the Maya, and to fill in their largest hole between 200 and 600 AD, but they’ve measured the Earth’s deceleration at 1.8 milliseconds per day per century. Given the moon’s gravitational effect on our oceans, the discovery that Earth is decelerating isn’t a surprise, notes the Christian Science Monitor, though astronomers had previously estimated a higher rate.

1.Why are days longer than before according to the text?

A.The earth rotates more and more slowly.

B.Humanity has got incorrect timekeeping records.

C.It takes longer for the earth to turn around the sun.

D.The lost milliseconds for centuries are added to our present days.

2.How did researchers come to the conclusion of the study?

A.By resetting the rotating time of the earth.

B.By referring to ancient timekeeping records.

C.By studying the moon’s gravitational effect on the oceans.

D.By measuring time again with an atomic clock.

3.What can we infer about the study from what the geographer said?

A.Geography theory supports the result of the study.

B.The geographer disagrees to the research conclusion.

C.The scientists’ research is meaningless.

D.It’s right to get geographers involved in the study.

4.What is the meaning of the underlined word “deceleration” in Paragraph 2?

A.Evolution. B.Slow down.

C.Enlargement. D.Development.

Answer

1.A

2.B

3.A

4.B

【解析】

这是一篇科普文，主要讲述了有关时间变化的研究，由于地球自转速度逐渐变慢导致天数变长，研究者们通查阅古代时间记载得出相关结论。通过这篇科普文，我们了解到更多有关科学的知识。

1.推理判断题。由文章第一段中“The new research in the Proceedings of the Royal Society A shows that it takes the Earth a tiny bit longer these days to complete a single rotation (转动) than it did millions of years ago.”可知，发表在《英国皇家学会学报》上的一项新研究表明，与数百万年前相比，现在地球完成一次自转所花的时间要稍微长一点。由此判断出地球转动需要花费更长的时间，也就是地球转动速度变慢了，故选A。

2.推理判断题。由文章第一段中“Maybe more remarkable is that the work is the result of a tireless 40-year research into ancient timekeeping records dating back 2,700 years.”可知，也许更值得注意的是，这项工作是对2700年前的古代计时记录进行40年不懈研究的结果。以及下文中多次提及古代记录数据可判断出研究者们通过查阅古代时间记录得到调研结果。故选B。

3.推理判断题。由文章第二段中 “The most astonishing thing about this study is the fact that we have this information at all,” said a geographer not involved in the study. ”可知，这项研究最令人吃惊的地方在于，我们完全掌握了这些信息，”一位未参与研究的地理学家说。由此判断出得该地理专家认为地理为调查结果提供了理论基础。故选A。

4.词句猜测题。由划线处下文“Given the moon’s gravitational effect on our oceans, the discovery that Earth is decelerating isn’t a surprise,”可知，考虑到月球对我们海洋的引力作用，发现地球正在减速并不奇怪。所以通过上下文的语境可以判断出，划线词的意思为“减速”。故选B。