Question

    How much do you know about Earth-the planet that we live on? Our knowledge of Earth has been developing since ancient times. However, many puzzles about Earth remain unsolved. Live Science has published a list of the eight biggest mysteries about Earth. Let's look at some of them.

Where did water come from?

When it first came into being 4.5 billion years ago, Earth was a dry rock. So where did all of our water come from? Scientists think that it might have arrived in the form of ice by an asteroid(小行星) from outer space that hit our planet. But this theory has not been confirmed because there is very little related evidence(相关证据)to be studied.

What's in the core(地核)?

Scientists used to study meteorites(陨石)as small examples of Earth, believing that Earth's core was made of iron and nickel(镍). However, a later study in the 1950s proved this way to be wrong because it found that Earth would be too light to provide gravity if its core contained only iron and nickel. Today, scientists continue to bring forward different theories, but none have been confirmed.

How was the Moon born?

Scientists have found that the chemical compositions(成分)of Earth and the Moon are very similar. That suggests that the Moon actually came from Earth. For example, it could be a piece of Earth that separated when Earth hit another planet. It is also possible that when Earth first came into being, it spun(旋转)very fast and threw off enough molten(熔化的)rock to later from the Moon.

1.What's the story mainly about?

A.How Earth came into being. B.Where Earth's water came from.

C.How the Moon was formed. D.Unexplained mysteries about Earth.

2.What do we know about where water may come from?

A.Earth's water may come from ice that melted 4.5 billion years ago.

B.Earth's water may come from a small planet that hit Earth.

C.We don't know where water came from.

D.There is lots of evidence that tells us where water came from.

3.What does the underlined phrase "bring forward" in Paragraph 5 probably mean?

A.Check. B.Raise. C.Improve. D.Receive.

4.Which of the following is TURE according to the passage?

A.Scientists believed Earth's core was made of meteorites.

B.A study in the 1950s proved that Earth's core is made of iron and nickel.

C.The Moon and Earth are made of similar materials.

D.Three possibilities of where the Moon came from are mentioned.

Answer

1.D

2.B

3.B

4.C

【解析】

《生活科学》杂志公布了关于地球的八大谜团，本文主要介绍了无法解释的地球之谜中的几个。

1.主旨大意题。A：地球是如何形成的。B：地球上的水来自哪里。C：月球是如何形成的。D：无法解释的地球之谜。根据“Live Science has published a list of the eight biggest mysteries about Earth. Let's look at some of them.”及全文内容可知，本文主要讲述无法解释的地球之谜中的几个。故选D。

2.细节理解题。根据“Scientists think that it might have arrived in the form of ice by an asteroid(小行星) from outer space that hit our planet.”可知，地球上的水可能来自一个撞击地球的小行星。故选B。

3.词句猜测题。A：检查；B：筹集，提高（水平、数量等）；C：改善，提高；D：收到。分析“Today, scientists continue to bring forward different theories, but none have been confirmed.”可知，今天，科学家们继续提出不同的理论，但没有一个得到证实。此处强调“提出（提高理论的数量）”。故选B。

4.推理判断题。A：科学家认为地球的核心是由陨石构成的。根据“Scientists used to study meteorites(陨石)as small examples of Earth, believing that Earth's core was made of iron and nickel(镍).”可知，科学家认为地球的核心是由铁和镍构成的，该项表述错误；B：20世纪50年代的一项研究证明，地核是由铁和镍构成的。根据“Scientists used to study meteorites(陨石)as small examples of Earth…if its core contained only iron and nickel.”可知，20世纪50年代的一项研究证明，地核是由铁和镍构成的这个观点是错误的，该项表述错误；C：月球和地球是由类似的物质构成的。根据“Scientists have found that the chemical compositions(成分)of Earth and the Moon are very similar.”可知，科学家发现月球和地球是由类似的物质构成的，该项表述正确；D：文中提到了月球从何而来的三种可能性。根据“For example, it could be a piece of Earth…It is also possible that…”可知，文中提到了月球从何而来的两种可能性，该项表述错误。故选C。