2020成都七中三诊模拟英语试题附参考答案(3)

About a year ago，NASA offered $125,000 to Anjan Contractor，a 3-D technology expert, to build a device that would allow astronauts to make pizza on demand. The mechanical engineer promised that his invention would produce pies in large quantities that looked, tasted and even smelled like pizza made in common ovens.

Late last year, the engineer presented a video of his first prototype(原型) that begins by creating a single slice of dough (面团) that is cooked and printed at the same time. Then comes the tomato “sauce”— a mix of tomato powder，oil and water and finally, a protein slice that resembles cheese. While the video doesn’t show the baking process，the inventor says that once the pizza is printed，it can be ready to be consumed in 7 seconds.

While the pie in the video looks delicious enough to attract any pizza lover, Anjan Contractor is far from ready for astronauts. That’s because he still has to find a solution to make the food container in the printer last for 30 years. Though that may sound unrealistic, actually it is not.

Anjan Contractor believes that the only way that is possible is that the water is removed from all the ingredients(配料) and then they are reduced to the powder form. This, as you can imagine, will not be so easy. But, while the printer may not be ready for space, it certainly looks ready enough for people on earth.

Hopefully，NASA and Contractor will consider selling it to those not fortunate enough to go to Mars!

28. Why does the author mention the things that astronauts in space cannot do?

A. To ask us not to take common things for granted. B. To show they live a difficult life there.

C. To show their life is boring in space.       D. To introduce the topic of the text.

29. NASA offered $125,000 to Anjan Contractor mainly to ________.

A. create some new type of 3-D printer

B. attract more companies to work for NASA

C. help astronauts in space enjoy fresh pizza one day

D. produce pizza in large quantities to earn great profits

30. The biggest challenge that Anjan Contractor is faced with now is probably that ________.

A. he has no mone

B. y left to go on with his research

C. the pizza doesn’t seem appetizing to pizza lovers

D. he has no way to make pizza that can last for thirty years

E. he cannot make the food container last for decades

31. What’s the best title of the passage?

A. NASA is trying its best to help astronauts eat better

B. Astronauts may soon be able to enjoy steaming hot pizza

C. NASA is working on making pizza for common people D. A 3-D pizza printer has been used to make pizza

D

Following the outbreak of the novel coronavirus pneumonia (NCP)，also named COVID-19 by WHO, there is a general fear of the unknown virus as its full effects remain to be seen. Fever, coughing, sore throat, difficulty breathing – the NCP’s symptoms are similar to the common cold or the flu, but it’s potentially more dangerous.

Viruses could be deadly, like HIV and Ebola. But what are viruses? How can they cause so much trouble?

Viruses are non-living organisms approximately one-millionth of an inch long. Unlike human cells or bacteria, they can’t reproduce on their own. Instead, they invade the cells of living organisms to reproduce, spread and take over.

Viruses can infect every living thing – from plants and animals down to the smallest bacteria. For this reason, they always have the potential to be dangerous to human life. Sometimes a virus can cause a disease so serious that it is fatal. Other viral infections trigger(引发) no noticeable reaction.

Viruses lie around our environment all of the time, waiting for a host cell to come along. They can enter our bodies by the nose, mouth, eyes or breaks in the skin. Once inside, they try to find a host cell to infect. For example, HIV, which causes AIDS, attacks the T-cells of the immune system.

But the basic question is, where did viruses first come from? Until now, no clear explanation for their origin exists. “Tracing the origins of viruses is difficult,” Ed Rybicki, a virologist at the University of Cape

Town in South Africa, told Scientific American, “because viruses don’t leave fossils and because of the tricks they use to make copies of themselves within the cells they’ve invaded.”

However, there are three main hypotheses (假说) to explain the origin of viruses. First, viruses started as independent organisms, then became parasites (寄生者). Second, viruses evolved from pieces of DNA or RNA that “escaped” from larger organisms. Third, viruses co-evolved with their host cells, which means they existed alongside these cells.