单选题

Batteries Built by Viruses

What do chicken pox, the common cold, the flu, and AIDS have in common? They're all disease caused by viruses, tiny microorganisms that can pass from person to person. It's no wonder that when most people think about viruses, finding ways to steer clear of viruses is what's on people's minds.
Not everyone runs from the tiny disease carriers, though. In Cambridge, Massachusetts, scientists have discovered that some viruses can be helpful in an unusual way. They are putting viruses to work, teaching them to build some of the world's smallest rechargeable batteries.
Viruses and batteries may seem like an unusual pair, but they're not so strange for engineer Angela Belcher, who first came up with the idea. At the Massachusetts Institute of Technology (MIT) in Cambridge, she and her collaborators bring together different areas of science in new ways. In the case of the virus-built batteries, the scientists combine what they know about biology, technology and production techniques.
Belcher's team includes Paula Hammond, who helps put together the tiny batteries, and Yet-Ming Chiang, an expert on how to store energy in the form of a battery. "We're working on things we traditionally don't associate with nature," says Hammond.
Many batteries are already pretty small. You can hold A, C and D batteries in your hand. The coin-like batteries that power watches are often smaller than a penny. However, every year, new electronic devices like personal music players or ceil phones get smaller than the year before. As these devices shrink, ordinary batteries won't be small enough to fit inside.
The ideal battery will store a lot of energy in a small package. Right now, Belcher's model battery, a metallic disk completely built by viruses, looks like a regular watch battery. But inside, its components are very small—so tiny you can only see them with a powerful microscope.
How small are these battery parts? To get some ideas of the size, pluck one hair from your head. Place your hair on a piece of white paper and try to see how wide your hair is—pretty thin, right? Although the width of each person's hair is a bit different, you could probably fit about 10 of these virus-built battery parts, side to side, across one hair. These microbatteries may change the way we look at viruses.

单选题 According to the first paragraph, people try to ______.

A.kill microorganisms related to chicken pox, the flu, ere
B.keep themselves away from viruses because they are invisible
C.stay away from viruses because they are causes of various diseases
D.cure themselves of virus-related diseases by taking medicines

单选题 What is Belcher's team doing at present?

A.It is finding ways to get rid of viruses.
B.It is mass-producing microbatteries.
C.It is making batteries with viruses.
D.It is analyzing virus genes.

单选题 What expression below is opposite in meaning to the word "shrink" appearing in paragraph 5?

A.Broaden.
B.Spread.
C.Extend.
D.Expand.

【正确答案】 D

【答案解析】[解析] 根据第五段最后一句“As these devices shrink, ordinary batteries won't be small enough to fit inside.”可推断shrink此处意为“缩小”，所以D项expand“扩大，增大”为正确答案。A项broaden“变宽”，C项extend“延伸，加长”都不合适。B项spread“伸展，展开”在一定的语境里，可以作为shrink(收缩)的反义词，但此处上下文里，显然B项也不适合。故本题选D。

单选题 Which of the following is true of Belcher's battery mentioned in paragraph 6?

A.It is made of metal.
B.It is a kind of watch battery.
C.It can only be seen with a microscope.
D.It is a metallic disk with viruses inside it.

【正确答案】 D

【答案解析】[解析] 根据本段第二句“Belcher's model battery, a metallic disk completely built by viruses...inside, its components are very small—so tiny you can only see them with a powerful microscope.”可知Belcher制作的电池外部是金属，内部是由病毒构成的部件，所以A项错误，D项正确。而且这种电池看起来像普通的手表电池，所以B项错误。本句说其部件很小，只能用显微镜才能看到，所以C项错误。故本题选D。