【题目】Batteries can power anything from small sensors to large systems. While scientists are finding ways to make them smaller but even more powerful, problems can arise when these batteries are much larger and heavier than the devices themselves. University of Missouri(MU) researchers are developing a nuclear energy source that is smaller, lighter and more efficient.

“To provide enough power, we need certain methods with high energy density(密度)”, said Jae Kwon, assistant professor of electrical and computer engineering at MU. “The radioisotope(放射性同位素) battery can provide power density that is much higher than chemical batteries.”

Kwon and his research team have been working on building a small nuclear battery, presently the size and thickness of a penny, intended to power various micro / nanoelectromechanical systems (M/NEMS). Although nuclear batteries can cause concerns, Kwon said they are safe.

“People hear the word ‘nuclear’ and think of something very dangerous,” he said, “However, nuclear power sources have already been safely powering a variety of devices, such as pace-makers, space satellites and underwater systems.”

His new idea is not only in the battery’s size, but also in its semiconductor(半导体). Kwon’s battery uses a liquid semiconductor rather than a solid semiconductor.

“The key part of using a radioactive battery is that when you harvest the energy, part of the radiation energy can damage the lattice structure of the solid semiconductor,” Kwon said, “By using a liquid semiconductor, we believe we can minimize that problem.”

Together with J. David Robertson, chemistry professor and associate director of the MU Research Reactor, Kwon is working to build and test the battery. In the future, they hope to increase the battery’s power, shrink its size and try with various other materials. Kwon said that battery could be thinner than the thickness of human hair.

1Which of the following is true of Jae Kwon?

A. He teaches chemistry at MU.

B. He is working on a nuclear energy source.

C. He developed a chemical battery.

D. He made a breakthrough in computer engineering.

2Jae Kwon gave examples in Paragraph 4_________.

A. to introduce nuclear batteries can be safely used

B. to show chemical batteries are widely applied

C. to introduce various energy sources

D. to describe a nuclear-powered system

3Liquid semiconductor is used to _________.

A. get rid of the radioactive waste

B. test the power of nuclear batteries.

C. reduce the damage to lattice structure.

D. decrease the size of nuclear batteries

【题目】Frederick Callison has been posting up outside of a Sacramento Smart & Final grocery store for the past two years and his method of looking for help has finally paid off.

Michael Marteen noticed Callison while shopping with his family on Feb. 24. Used to seeing homeless people ask for food and money, Marteen found it refreshing to see someone making an effort to find work in such difficult situations.

When Marteen approached him, he noticed Callison was sitting on a sleeping bag with several resumes(简历)neatly laid out, along with a sign that read“need work and food.”

“When I asked if I could see his resume, he stood right up to hand one to me and then started telling me all about his experience as if it were an interview,”Marteen toldTODAY. “I’ve been in situations where I had nothing and had to try extremely hard to get work, and there he was doing that, so I have a lot of respect for him.”

Marteen bought him a bottle of water and some ravioli(馄饨)and then took a picture of his resume to post on Facebook, not knowing if anything would come of it.

Sure enough, someone came across his post and offered Callison a job as a cook at a downtown restaurant called Pizza Rocks.

“He was excited about landing a job and very grateful for the opportunity,” Marteen said. “He was up the night before studying the menu for hours.”

The restaurant gave him clothes to wear and a friend is providing Callison with a place to stay until he can get back on his feet.

“It’s easy to look at someone and not see anything but a homeless man, but after talking to him I realized he’s so much more than that,” Marteen said. “He’s a well spoken, cool and friendly guy who knows what he wants and is going after it.”

1What is the passage mainly about?

A. Homeless Callison landed a job.

B. Homeless Callison was helped by Facebook.

C. Homeless Callison dreamed big.

D. Homeless Callison lived a hard life.

2What makes Callison different from other homeless people?

A. He begged at the same place for two years.

B. He had a sleeping bag with him.

C. He is friendly, cool and well spoken.

D. He was looking for a job while begging.

3What does the underlined word in Paragraph 2 mean?

A. Pitiful. B. Unforgettable.

C. Strange and interesting. D. Unbelievable.

4What can we infer about Callison after he was offered a job?

A. He was offered clothes by the restaurant.

B. He took his job seriously.

C. He couldn't walk properly.

D. He would soon become rich.

【题目】Memphis Meats, a San Francisco startup company trying to create lab-grown meat from animal cells(细胞), released a video on Tuesday that shows the world’s first cultured meatball getting fried up in a pan.

“We watched how the meatball reacted in the pan, we heard the sizzle, we smelled the meat and it was exactly how you would expect a meatball to smell,” Memphis Meats chief executive Uma Valeti said in the video. “This is the first time a meatball has ever been cooked with beef cells that didn’t need a cow to be killed.”

Memphis Meats grows animal muscle tissue(组织) using stem cells of cows and pigs and feeds them oxygen and nutrients(营养物质), according to the Wall Street Journal. While there are no animals killed in making the meats, the firm does use fetal bovine serum(胎牛血清) from unborn cattle's blood to start the process.

So far, the cells grow in extremely thin layers, which is very expensive. Now it costs about $18,000 to produce a pound of Memphis Meats beef--compared to about $4 for store-bought beef.

But the company, founded by three scientists, has been experimenting growing meat from stem cells from cows, pigs, and chickens and says it’ll be selling its animal-free products to high-end customers in three to four years.

The company’s first line of products will include hot dogs, sausages, burgers and meatballs.

Valeti said in the video that his company’s process also produces 90 percent fewer greenhouse gases than traditional agriculture.

“The meat industry knows their products aren’t sustainable(可持续的),” Valeti told the Wall Street Journal. “We believe that in 20 years, a majority of meat sold in stores will be cultured.”

It’s too early to say if we’ll all be cooking lab-grown meatballs, chicken wings, and pork chops. But for now, there is a big push to be the first to bring these foods to our plates.

1What can be the best title for the passage?

A. Lab-grown meat is to hit the market.

B. Lab-grown meat smells as delicious.

C. Lab-grown meat is animal-free.

D. Lab-grown meat will replace traditional meat soon.

2What’s the biggest disadvantage of the lab-grown meat?

A. It is difficult to grow.

B. It is too expensive.

C. It is difficult to be accepted by customers.

D. It doesn’t have many varieties.

3What can we know about the lab-grown meat?

A. The layers where it grows are very expensive.

B. Cattle’s blood is needed to feed the cells.

C. Lab-grown meat has nothing to do with animals.

D. The growing process costs a lot.

4What can we infer from the passage?

A. Lab-grown meat tastes exactly like traditional meat.

B. Traditional meat industry is not sustainable.

C. Lab-grown meat is environmentally friendly.

D. Lab-grown meat is best suitable for frying.

【题目】根据短文内容, 从短文后的七个选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

【1】You probably think you will never be a top student. This is not necessarily so. however. Anyone can become a better student if he or she wants to. Here is how

Plan your time carefully. When planning your work, you should make a list of things that you have to do. After making this list. you should make a schedule of your time. First your time for eating, sleeping, dressing, etc. Then decide a good, regular time for studying. 【2】 A weekly schedule may not solve all your problems, but it will force you realize what is happening to your time.

Find a good place to study. Look around the house for a good study area. Keep this space, which may be a desk or simply a corner of your room, free of eeverything but study materials. No games, radios, or television. When you sit down to study, concentrate on the subject.

Make good use of your time in class. 【3】 Listening carefully in class means less work later. Taking notes will help you remember what the teacher says.

Study regularly. When you get home from school, go over your notes, review the important points that your teacher is going to discuss the next day, read that material. 【4】 If you do these things regularly, the material will become more meaningful, and you’ll remember it longer.

Develop a good attitude towards tests. The purpose of a test is to show what you have learned about a subject. They help you remember your new knowledge. The world won’t end if you don’t pass a test,so don, t be over worried.

【5】 You will probably discover many others after you have tried these.

A. There are other methods that might help you with your studying.

B. Don’t forget to set aside enough time for entertainment.

C. Take advantage of class time to listen to everything the teacher says.

D. No one can become a top student unless he or she works hard.

E. Maybe you are an average student.

F. Make full use of class time to take notes of what the teacher says in class.

G. This will help you understand the next class.

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