D
Earth is the third planet from the sun. It is one of the four inner planets. The other three inner planets are Mercury, Venus, and Mars. The inner planets are also called the rocky planets, because they are made of rocks.
Earth is often called the “Water Planet”, because it is the only planet in our solar system which has liquid water on its surface. About 70% of the surface of Earth is covered by water! The other part of Earth is made up of continents and islands which have different landforms on them. Examples of landforms are mountains and plains. Plants and animals can live on Earth, because it has so much water.
Earth spins very quickly compared to other planets. It only takes Earth 24 hours to spin around its axis one time. One Earth day is 24 hours long! Earth orbits the sun in 365 days! This makes one Earth year 365 days long!
Earth is the only planet in our solar system where humans, other animals, and plants can live. There is plenty of water to drink or to live in. Water is present on Earth in its big oceans and in the air! Clouds are made of water vapor. The atmosphere has a lot of oxygen in it for animals to breathe, but the rest of our “air” is made up of water vapor, nitrogen, carbon dioxide, and other gases. The air is perfect for plants to grow. Earth temperature is not the same in all places, but the temperature is just right for plants, animals, and humans in most places on Earth.
Like the other inner planets, Earth has volcanoes. Volcanoes on Earth are different from those on other planets, because they still erupt. Scientists think that there may be active volcanoes on other planets and moons in our solar system, but they are still studying this.
Earth has one planet which we call the Moon. The surface of the Moon has many craters on it These were caused when meteorites hit it. It has many volcanoes on it which do not erupt anymore. We can see the moon at night without using a telescope. It is the closest space object to our planet ,Earth.
68.Earth is called the Water Planet,______.
A. because animals need water         B. the water makes it look blue from space
C. it has liquid water on its surface      D. Earth is the third planet from the sun
69. It takes Earth ______to orbit the sun in one year.
A.24 hours                   B.24 days                     C.365 days                   D.360 days
70. Life exists on Earth,______.
A. because the water, air, and temperature are just right
B. there is water vapor in clouds
C. Earth is the planet closest to the sun
D. earth has volcanoes
71.The craters on the moon were caused by______.
A. meteorites hitting its surface              B. active volcanoes
C. volcanoes which do not erupt anymore      D. some reasons that are not mentioned

Earth is the third planet from the sun.It is one of the four inner planets.The other three inner planets are Mercury,Venus,and Mars.The inner planets are also called the rocky planets,because they are made of rocks.

Earth is often called the “Water Planet”,because it is the only planet in our solar system which has liquid water on its surface.About 70% of the surface of Earth is covered by water! The other part of Earth is made up of continents and islands which have different landforms on them.Examples of landforms are mountains and plains.Plants and animals can live on Earth,because it has so much water.

Earth spins very quickly compared to other planets.It only takes Earth 24 hours to spin around its axis one time.One Earth day is 24 hours long!Earth orbits the sun in 365 days! This makes one Earth year 365 days long!

Earth is the only planet in our solar system where humans,other animals,and plants can live.There is plenty of water to drink or to live in.Water is present on Earth in its big oceans and in the air! Clouds are made of water vapor.The atmosphere has a lot of oxygen in it for animals to breathe,but the rest of our “air” is made up of water vapor,nitrogen,carbon dioxide,and other gases.The air is perfect for plants to grow.Earth temperature is not the same in all places,but the temperature is just right for plants,animals,and humans in most places on Earth.

Like the other inner planets,Earth has volcanoes.Volcanoes on Earth are different from those on other planets,because they still erupt.Scientists think that there may be active volcanoes on other planets and moons in our solar system,but they are still studying this.

Earth has one planet which we call the Moon.The surface of the Moon has many craters on it These were caused when meteorites hit it.It has many volcanoes on it which do not erupt anymore.We can see the moon at night without using a telescope.It is the closest space object to our planet,Earth.

Earth is called the Water Planet,______.

A.because animals need water

B.the water makes it look blue from space

C.it has liquid water on its surface

D.Earth is the third planet from the sun

It takes Earth ______to orbit the sun in one year.

A.24 hours                 B.24 days                   C.365 days                 D.360 days

Life exists on Earth,______.

A.because the water,air,and temperature are just right

B.there is water vapor in clouds

C.Earth is the planet closest to the sun

D.earth has volcanoes

同义转换（共5小题；每小题1分，满分5分）

请认真阅读下列句子，根据中文在空格处填上最恰当的词。每空格一个单词。

1. Matthew probably felt guilty about not having such a gift for football as you do.

 Matthew probably felt guilty about not being as ___________ at football as you are.

2. The factory keeps giving off smoke. As a result, the air is made dirty.

 The factory keeps giving off smoke, ___________ the air dirty.

3. Two people were arrested yesterday at a Paris airport because they brought animals into Europe from South Africa, which is against the law.

Two people were arrested yesterday at a Paris airport for bringing animals into Europe from South Africa ___________.

4. The new plan will change the British film industry in every way.

The new plan will _________ the British film industry.

5. Asking around, I find many people willing to pay a little higher price for things that are friendly to the environment.

Asking around, I find many people willing to pay a little higher price for things that are _____ friendly.

Clean air is made up of only nitrogen, oxygen, and water. As we have industrialized, our cities have grown and traffic has increased. With these development there has come an increase in the number of by-products released into the air, such as particles（细粒）from burning fuels and poisonous gases from chemical reactions. These gases become pollutants.

Air pollution has a bad effect on the earth and our environment. Air pollution can result in acid rain, and it can also lead to the Greenhouse Effect—a condition in which pollution stops radiation from traveling out of the Earth’s atmosphere. This upset to the natural process means that temperatures on Earth may not be maintained within natural ranges. Due to the Greenhouse Effect, temperatures on Earth become warmer, which is known as global warming. What’s worse, air pollution may produce holes in the ozone layer（臭氧层）— this layer of ozone naturally prevents ultra-violet rays （紫外线） from the sun reaching Earth. Holes make it possible for the rays to reach us.

Don’t let all the bad news about air pollution get you down because there are many ways to help fight the air pollution. Every one of us can employ a variety of air pollution solutions. A smoker can give up smoking. While shopping, you can choose organic and natural cleaning products. Driving less and carpool more can also contribute to less pollution. Next time, keep your air-conditioning low. Of course you can plant more trees.

Air pollution is a major problem for our planet. However, as long as we realize how serious the air pollution is and take actions now, everyone can make a difference!

                     Title:71.         

Earth is the third planet from the sun.It is one of the four inner planets.The other three inner planets are Mercury,Venus,and Mars.The inner planets are also called the rocky planets,because they are made of rocks.

Earth is often called the “Water Planet”,because it is the only planet in our solar system which has liquid water on its surface.About 70% of the surface of Earth is covered by water! The other part of Earth is made up of continents and islands which have different landforms on them.Examples of landforms are mountains and plains.Plants and animals can live on Earth,because it has so much water.

Earth spins very quickly compared to other planets.It only takes Earth 24 hours to spin around its axis one time.One Earth day is 24 hours long!Earth orbits the sun in 365 days! This makes one Earth year 365 days long!

Earth is the only planet in our solar system where humans,other animals,and plants can live.There is plenty of water to drink or to live in.Water is present on Earth in its big oceans and in the air! Clouds are made of water vapor.The atmosphere has a lot of oxygen in it for animals to breathe,but the rest of our “air” is made up of water vapor,nitrogen,carbon dioxide,and other gases.The air is perfect for plants to grow.Earth temperature is not the same in all places,but the temperature is just right for plants,animals,and humans in most places on Earth.

Like the other inner planets,Earth has volcanoes.Volcanoes on Earth are different from those on other planets,because they still erupt.Scientists think that there may be active volcanoes on other planets and moons in our solar system,but they are still studying this.

Earth has one planet which we call the Moon.The surface of the Moon has many craters on it These were caused when meteorites hit it.It has many volcanoes on it which do not erupt anymore.We can see the moon at night without using a telescope.It is the closest space object to our planet,Earth.

73.Earth is called the Water Planet,______.

A.because animals need water

B.the water makes it look blue from space

C.it has liquid water on its surface

D.Earth is the third planet from the sun

74It takes Earth ______to orbit the sun in one year.

A.24 hours                   B.24 days                     C.365 days                   D.360 days

75Life exists on Earth,______.

A.because the water,air,and temperature are just right

B.there is water vapor in clouds

C.Earth is the planet closest to the sun

D.earth has volcanoes