Question

If you want to slow aging, you might want to eat less. This finding is good news---if you were a mouse. The researchers studied mice, not people.

John Price and other researchers studied two groups of mice. One group was able to eat as much as it wanted. The researchers limited what the mice in the other group ate. Their diet had 35 percent fewer calories than the first group of mice.

Price says the mice with the diet restrictions were “more energetic and suffered fewer disease.” They were not just living longer but seemed to stay younger for a longer period of time.

The researchers found that fewer calories slow down a natural mechanism in cells called ribosomes. Price explains that ribosomes are responsible for making important proteins in the cells. But with fewer calories, they slow down. This gives the cells more time to repair themselves.

The researchers say ribosomes use from 10 to 20 percent of the cell’s energy to make those proteins. Price wrote that “because of this, it is impractical to destroy an entire ribosome” when it starts to break down. However, “repairing individual parts of the ribosome on a regular basis enables ribosomes to continue producing high quality proteins for longer than they would otherwise. This top quality production, in turn, keeps cells and the entire body functioning well.”

Price said, “ribosome is a very complex machine, like a car.” They need “maintenance to replace the parts that wear out the fastest. When tires wear out,” he explained, “you don’t throw the whole car away and buy a new one. It costs less to replace the old tires.”

“Food,” he said, “isn’t just material to be burned---it’s a signal that tells our body and cells how to respond.” Price said the findings help to explain how exactly our bodies age. And this may “help us make more educated decisions about what we eat.”

1.What can we know about the mice with limited calories from the study?

A. They can keep healthy easily

B. They need more energy to be active

C. They can look younger than they are

D. They will live a longer life like humans

2.What will happen to ribosomes if there are fewer calories?

A. They will completely break down

B. They make proteins in the cells slowly

C. They will produce high quality proteins more

D. They may need more time to repair themselves

3.Price explained the ribosomes’ role of repairing themselves by _________.

A. telling a story

B. listing basic data

C. making comparisons

D. experimenting on mice

4.What does the text mainly deal with?

A. Food decides how long you live

B. Can you slow down your aging process?

C. Eating less may help you live longer

D. Should your diet be reduced for your health?

Answer

1.A

2.B

3.C

4.C

【解析】 本文属于科技与发明类。主要介绍了通过在老鼠身上所作的实验，发现减少食物有利于身体建康，让人更长寿。

1.A

推理判断题。根据第三段“the mice with the diet restrictions were “more energetic and suffered fewer disease”饮食限制的老鼠更精力充沛，患疾病的几率也更小。根据句意可知限制饮食的老鼠更健康，故选A。

2.B

推理判断题。根据第四段句意：研究人员发现更少的热量减慢了称为核糖体的细胞的自然机制。 Price说明核糖体负责制造细胞中重要的蛋白质。但是热量越少，它们就制造的速度越慢。分析本句可知核糖体在细胞中制造蛋白质的速度减慢了。故选B。

3.推理判断题。根据第六段：普赖斯说：“核糖体是一个非常复杂的机器，就像一辆汽车。”他们需要“维修”来替换最快磨损的部件。“当轮胎磨损时，”他解释道，“你不要把车全扔掉，买一辆新的。”。更换旧轮胎成本较低。” 普赖斯把核糖体比作是一辆非常复杂的汽车， 可知是通过比较的，故选C。

4.D

主旨大意题。根据第一段可知想要年轻就要少吃。第三段限制食物的老鼠要更活跃更健康。及最后一段这可能会“帮助我们对我们所吃的东西做出更多的教育决定”。可知为了建康应该减少食物。故选D。