It’s difficult to imagine now, but at certain...

It’s difficult to imagine now, but at certain points in the Earth’s history, ice covered the entire planet. This frozen Earth, nicknamed Snowball Earth, was “so severe that the Earth’s entire surface, from pole to pole, including the oceans, completely froze over”, said Melissa Hage, an environmental scientist at Emory University in Georgia.

In 1840, Louis Agassiz, a Swiss natural scientist, was among the first to acknowledge and provide evidence that the Earth had gone through ice ages. Joseph Kirschvink, an American geologist, later created the term “Snowball Earth” in a 1992 textbook.

Scientists believe that four severe ice ages occurred between 750 million and 580 million years ago, probably because the Earth’s lands were all located at or near the equator (赤道), which resulted in increased weathering (风化). Weathering is happening when wind and rain break down rocks and minerals on the planets surface. The process leads to decreased carbon dioxide levels in the atmosphere, which allows more heat to get away from the surface and into space, cooling the planet, causing the planet into a deep freeze.

The severe ice ages eventually melted away. Scientist believe that volcanoes continued to pump carbon dioxide into the atmosphere throughout the ice ages, eventually warming the planet enough that the water cycle could restart. As the Earth warmed and came out of its deep freeze. a huge explosion of life occurred. known as the Cambrian (寒武纪) explosion.

Will we see another Snowball Earth in our future? According to Hage, it’s unlikely, due to the spread-out of the continents. “Even with extreme winters, continental ice sheets would form, which would stop continental weathering and allow carbon dioxide to build up in the atmosphere, leading to warming rather than freezing,” she said.

1.How many severe ice ages occurred between 750 million and 580 million years ago according to the passage?

A.Three. B.Four.

C.Five. D.Six.

2.What do we know about the Earth according to the passage?

A.The term “Snowball Earth” was first used in 1840.

B.Millions of years ago, the Earths lands weren’t where they are now.

C.Weathering was the main factor of warming the Earth.

D.The Earth was completely covered with ice during the Cambrian period.

3.What probably led to the end of the ice ages?

A.Heat’s escaping. B.An unknown reason.

C.Carbon dioxide from volcanoes. D.A force from the outer space.

4.What is the best title for the text?

A.Snowball Earth: The End of the Life

B.Some Severe lee Ages in the Earths History

C.Frozen Earth: Another lee Age Is Coming

D.Snowball Earth: Will the Blue Planet Go White Again?

高三英语阅读理解困难题查看答案及解析

It may be necessary to stop _____ in the learning process and go back to the difficult points in the lessons．

A． at intervals　　　　　 B． at random

C． at ease　　　　　　　　 D． at length

高三英语单项填空中等难度题查看答案及解析

It may be necessary to stop _____ in the learning process and go back to the difficult points in the lessons．

A． at intervals　　　　　 B． at random

C． at ease　　　　 　　 　 D． at length

高三英语单项填空困难题查看答案及解析

It may be necessary to stop______in the learning process and go back to the difficult points in the lessons.

A.at intervals B.at random

C.at ease D.at length

高三英语单项填空中等难度题查看答案及解析

It may be necessary to stop______in the learning process and go back to the difficult points in the lessons.

A. at intervals　　 B. at random

C. at ease　　 D. at length

高三英语单项填空中等难度题查看答案及解析

It is difficult for us to imagine_____ life was like for slaves in the ancient world.

A. where　　 B. what　　　　　 C. which　　　 D. why

高三英语单项填空中等难度题查看答案及解析

We are all called upon to make a speech at some point in life, but most of us don’t do a very good job.________1.________.

So, you have to give a speech—and you are terrified. You get nervous, you forget what you want to say, you stumble（结结巴巴） over words, you talk too long, and you bore your audience. Later you think, “Thank Goodness, it’s over. I’m just not good at public speaking. I hope I never have to do that again.”

Cheep up!________2.________. Here are some simple steps to take the pain out of speech making. Ask yourself the purpose of your speech. What is the occasion? Why are you speaking? Then, gather as many facts as you can on your subject. Spend plenty of your time doing your research. Then spend plenty of your time organizing your material so that your speech is clear and easy to follow. Use as many examples as possible, and use pictures, charts, and graphs if they help you make your points more clearly. ________3.________. Don’t talk down to them. Treat your audience with respect. They will appreciate your thoughtfulness.

Just remember: Be prepared. Know your subject, your audience, and the occasion. Be brief.________4.________. And be yourself. Let your personality come through so that you make person-to-person contact with your audience.

If you follow these simple steps, you will see that you don’t have to be afraid of public speaking. In fact, you may find the experience so enjoyable that you volunteer to make more speeches! You’re not convinced yet? ________5.________.

A. It doesn’t have to be that bad.

B. Take several deep breaths before your speech.

C. This article gives some advice on how to give a good speech.

D. Say what you have to say and then stop.

E. Don’t give a try to say what you aren’t familiar with.

F. Never forget your audience.

G. Give it a try and see what happens.

高三英语其他题中等难度题查看答案及解析

We are all called upon to make a speech at some point in life, but most of us don’t do a very good job. This article gives some suggestions on how to give an effective speech.

So, you have to give a speech—and you are terrified. You get nervous, you forget what you want to say, you stumble over words, you talk too long, and you bore your audience. Later you think, “Thank Goodness, it’s over. I’m just not good at public speaking. I hope I never have to do that again.”

Cheep up! It doesn’t have to be that bad. Here are some simple steps to take the pain out of speech making. Ask yourself the purpose of your speech. What is the occasion? Why are you speaking? Then, gather as many facts as you can on your subject. Spend plenty of your time doing your research. Then spend plenty of your time organizing your material so that your speech is clear and easy to follow. Use as many examples as possible, and use pictures, charts, and graphs if they help you make your points more clearly. Never forget your audience. Don’t talk over their heads, and don’t talk down to them. Treat your audience with respect. They will appreciate your thoughtfulness.

Just remember: Be prepared. Know your subject, your audience, and the occasion. Be brief. Say what you have to say and then stop. And be yourself. Let your personality come through so that you make person-to-person contact with your audience.

If you follow these simple steps, you will see that you don’t have to be afraid of public speaking. In fact, you may find the experience so enjoyable that you volunteer to make more speeches! You’re not convinced yet? Give it a try and see what happens.

1.The main idea of this article is________.

A．that it is hard to make a speech B．that a poor speaker can never change

C．to always make a short speech       D． that you can improve your speaking ability

2.Paragraph 2 implies that ________.

A．many people talk too long

B．many people are happy to give a speech

C．many people don’t prepare for a speech

D．many people are afraid of giving a speech

3.The phrase “talk over their heads” means ________.

A．speak too loudly                                   B．look at the ceiling

C．look down upon them              D．use words and ideas that are too difficult

4.All of the following statements are TRUE except ________.

A．a lecturer does not need to organize his speech

B．few people know how to make good speeches

C．research is important in preparing a speech

D．there are simple steps you can take to improve your speaking ability

5.The title for this passage may be ________.

A．Do Not Make a Long Speech        B．Try to Enjoy a speech

C．How to prepare for a Speech  D． How to Give a Good Speech

高三英语阅读理解中等难度题查看答案及解析

We are all called upon to make a speech at some point in life, but most of us don’t do a very good job. This article gives some suggestions on how to give an effective speech.

So, you have to give a speech—and you are terrified. You get nervous, you forget what you want to say, you stumble over words, you talk too long, and you bore your audience. Later you think, “Thank Goodness, it’s over. I’m just not good at public speaking. I hope I never have to do that again.”

Cheep up! It doesn’t have to be that bad. Here are some simple steps to take the pain out of speech making. Ask yourself the purpose of your speech. What is the occasion? Why are you speaking? Then, gather as many facts as you can on your subject. Spend plenty of your time doing your research. Then spend plenty of your time organizing your material so that your speech is clear and easy to follow. Use as many examples as possible, and use pictures, charts, and graphs if they help you make your points more clearly. Never forget your audience. Don’t talk over their heads, and don’t talk down to them. Treat your audience with respect. They will appreciate your thoughtfulness.

Just remember: Be prepared. Know your subject, your audience, and the occasion. Be brief. Say what you have to say and then stop. And be yourself. Let your personality come through so that you make person-to-person contact with your audience.

If you follow these simple steps, you will see that you don’t have to be afraid of public speaking. In fact, you may find the experience so enjoyable that you volunteer to make more speeches! You’re not convinced yet? Give it a try and see what happens.

1.The title for this passage may be ________.

A. Do Not Make a Long Speech    B. How to Give a Good Speech

C. How to prepare for a Speech  D. Try to Enjoy a speech

2.Paragraph 2 implies that.

A. many people are happy to give a speech

B. many people are afraid of giving a speech

C. many people don’t prepare for a speech

D. many people talk too long

3. The phrase “talk over their heads” means ________.

A. speak too loudly             B. look at the ceiling

C. look down upon them          D. use words and ideas that are too difficult4.All of the following statements are TRUE except ________.

A. not many people know how to make good speeches

B. a lecturer does not need to organize his speech

C. research is important in preparing a speech

D. there are simple steps you can take to improve your speaking ability

高三英语阅读理解中等难度题查看答案及解析

Please ____ the mistakes in my composition.

A．point to           B．point out          C．point at           D．point

高三英语单项填空中等难度题查看答案及解析