We know that about seventy percent _____ the ...

We know that about seventy percent _____ the earth _____ covered by water.

A. /; is　　　　 B. of; are

C. of; is　　 　 D. about; are

九年级英语单项填空简单题查看答案及解析

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.

九年级英语阅读单选中等难度题查看答案及解析

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 (谜) 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 idea has not been confirmed (证明) 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 (引力) if its core contained only iron and nickel. Today, scientists continue to bring forward different ideas, 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 form the Moon.

1.What’s the main idea of the passage?

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 TRUE according to the passage?

A.Scientists used to believe 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.

九年级英语阅读单选中等难度题查看答案及解析

About seventy percent of our earth _______ by water.

A. is covering　　 B. is covered

C. are covered　　 D. are covering

九年级英语单选题简单题查看答案及解析

We all know that the gravity on Mars is only about _________ of __________ on Earth.

A. three-eighths; the one　　 B. three-eighth; the one

C. three-eighths; that　　 D. three-eighth; that

九年级英语单选题中等难度题查看答案及解析

More than seventy percent of the earth ________ covered with water.

A.is B.are C.was D.were

九年级英语单选题中等难度题查看答案及解析

The gravity of the Mars is only about 37．5 percent of _________ of the Earth．

A. one B. it C. that D. those

九年级英语单选题困难题查看答案及解析

About seventy percent of the students_______ in playing computer games.

A. show interest　　 B. shows interest

C. show interests　　 D. is interested

九年级英语单选题简单题查看答案及解析

We all know that the earth is not the c________ of the universe(宇宙).

九年级英语单词拼写中等难度题查看答案及解析

任务型阅读 根据短文内容，回答下列问题。

Is there life on Mars? We don’t know．We’re sure that people on the earth are not able to live on Mars．People on the earth need oxygen to breathe in．There is almost no oxygen on Mars．

Living on Mars would be like living on a very high mountain．There would be little air．The temperature might be 50 degree above zero at noon and 140 degrees below zero at night．Many people think there may be plants on Mars．We know that on Mars there is carbon．This is a kind of material found in all plants and animals on the earth．Mars looks red through a telescope(望远镜)．It seems gray in some places．At times the gray color turn gray-green，then brown，then gray again．The gray-green color may be a kind of plant changing color with the seasons．

Will men go to Mars one day? If they do，they must take their own oxygen，food and clothing with them．

根据表格内容，完成下面各题。

1.Can people live on Mars?

2.Is there any oxygen on Mars?

3.What kind of material can be found in all plants and animals on the earth?

4.Does Mars look gray through a telescope?

5.What must men take if they go to Mars?

九年级英语其他题中等难度题查看答案及解析