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.
Every year, lots of people go to visit the Great Wall. The most popular section is Badaling (八达岭). However, during my seven years in China, Badaling never appeared attractive to me—there were too many tourists.
As an adventurous (爱冒险的) hiker, I prefer places that few people visit. One day in May 2000, I chose to visit Simatai. It is surrounded by thick forests and is extremely steep (陡峭的).
At the entrance, I met a group of vendors (小贩). They were selling some postcards. One tiny old woman followed me wherever I went. Finally, I became impatient. I shouted at her and ran away.
As soon as I saw the Great Wall, I felt extremely excited. The old woman had long disappeared from my mind. I raced up the Great Wall.
Then, halfway up, I stopped. Suddenly, I realized I was on a very dangerous path. It was no wider than a meter and there were no “walls”. It came to me that some tourists had fallen to their deaths there.
I felt terribly frightened. A cold wind came up. I stood there alone.
Suddenly, I felt a small hand on my back. A soft voice told me, in Chinese, not to be afraid. It said she would lead me to the top. And so she did—carefully and gently from behind. All the while, she repeated that everything would be fine.
Half an hour later, we reached a safer section. Feeling better, I turned around to see who had been so kind.
It was the old woman. I felt ashamed of myself and gave her a big hug. Later, I bought every one of her postcards. She smiled and took my hands in hers.
1.Where did the writer first meet the old woman?
A.Badaling. B.Halfway up to Simatai.
C.At the entrance. D.On a very dangerous path.
2.Why did the woman follow the writer all the time?
A.Because she wanted to help him.
B.Because she knew the writer would be in danger.
C.She was just a kind woman who wanted to sell postcards.
D.She was a volunteer in fact.
3.How did the woman help the writer?
A.By following him. B.By calming him down.
C.By standing behind him. D.By pushing him from behind.
4.What can we learn from the passage?
A.Where there is a will, there is a way.
B.Many hands make light work.
C.Never judge a book by its cover.
D.He who has never been to the Great wall is not a true man.
In our lives we are always playing games, because life itself is a game. Games are important for us to get knowledge and take decisions.
Games teach us to learn good or bad things. We can use the good things that the game teaches us in our lives. The bad things could do harm to our lives. Be careful with these bad things. Games can teach us bad or good things at the same time; in this case we need to separate very carefully what is bad from what is good to improve our lives.
Games teach us about history, economics (经济) and so on. Some games come with history knowledge and help us to learn very quickly about history. Economics is very important in our lives and games teach us about how the economics work.
Games can help us a lot when we make our own decisions. Because of games, we can do quickly, sure and right. We can make decisions very quickly after we practice games. Also we are sure about our decisions because when we play games we need to be very sure what we are doing. Decisions will be right because when we are playing games we learn to be right in our steps.
Playing games teaches me a lot in my life. I am able to talk about anything because I learn a lot of things from games.
1.Games are important because they can ______.
A.develop our social skills
B.make us care for others and the environment
C.make us feel happy and safe
D.help us get knowledge and take decisions
2.The underlined word “separate” in the passage probably means ______.
A.合并 B.区分 C.消除 D.增加
3.The third paragraph mainly discusses _____ .
A.games help us get knowledge
B.games help us make our own decisions
C.games help us deal with the problems of daily life
D.games develop our physical skills
4.Because of games, we can make _______ decisions.
A.wrong B.slow C.right D.big
A long time ago there was once a poor boy called Dick Whittington. The people in his village believed that the streets of London were paved with gold. So Dick decided to travel there.
When Dick arrived in London, he found there were no streets of gold! Tired and hungry, he fell asleep on the steps of a great house. It belonged to a rich businessman who gave Dick a job cleaning the kitchen. Dick had enough to eat and at night he could sleep by the fire. But at night, rats ran around and kept him awake. So Dick went out and found the fastest rat-catching cat in London. The cat caught all the rats that came into the house and Dick could sleep well at night.
The businessman heard about the amazing cat and asked Dick to take it on his ship to catch rats on his next journey. Soon the businessman returned and he was very happy because Dick’s cat had caught all the rats on the ship.
Dick worked hard for the businessman and learned everything he could. At last he married the businessman’s daughter and started a very successful business of his own.
1.Dick went to London because he wanted to ______.
A.see the beautiful sights there B.look for the cat that caught rats fast
C.marry the businessman’s daughter D.become a rich man
2.What did Dick do in the rich businessman’s house?
A.He cleaned the kitchen. B.He cooked food in the kitchen.
C.He cleaned the whole house. D.He drove the rats away from the kitchen.
3.The story has a ______ ending.
A.touching B.happy C.surprising D.sad
Pizza and French fries taste good. Unfortunately, kids in the United States are eating _______salty foods like them.
The salt we add to food is about 40% sodium(钠). Our bodies need some sodium to work _______, but too much of it is not healthy.
The Center for Disease Control (CDC) works to ______ people’s health. It studied the eating habits of more than 2,000 kids. It found that most kids eat about 1.5 teaspoons of sodium each day, which is almost double the ______ they should have.
This worried Zerleen Quader who works for the CDC. She is the lead author of the study. “Eating too ______ sodium now can set kids up for health problems later,” she said.
Researchers found that more than half the sodium kids eat _______ from packaged(袋装的) foods. Much of the sodium is in unlikely places.
Eating too much salt can raise blood pressure. That can lead to heart problems. Recently one in nine children has ________ blood pressure. There is good news, though. Eating less salt can lower blood pressure.
How can you cut back on the amount of salt in your diet? Kids at the age of 9 to 13 should get __________ more than 2,200 mg of sodium each day. For good health, look for foods with low or no sodium. Bridget Murphy is a nutrition(营养) expert. She says kids should try ______ spices (调味品) to food instead of salt. Try it, and your heart will ______ you. Eating more fruit and vegetables and cutting back on packaged and restaurant foods can also make a difference.
1.A.too many B.too much C.much too D.many too
2.A.lately B.nervously C.properly D.nearly
3.A.overcome B.protect C.examine D.prevent
4.A.place B.position C.energy D.amount
5.A.many B.much C.little D.few
6.A.divides B.dies C.comes D.leaves
7.A.dropped B.raised C.afforded D.expected
8.A.no B.hardly C.never D.seldom
9.A.wasting B.cutting C.adding D.eating
10.A.dislike B.thank C.hate D.master
—Your new dress looks nice. Could you tell me ______ ?
—Sure. I bought it from New Century Store.
A.how you bought it B.where did you buy it
C.where you bought it D.how did you buy it
