A person’s calorie requirements vary ________

For many years, humans have tried to find the secret to staying young. Although it has yet to be discovered, we may be closer than ever to finding a way that can slow down the aging process. A recent study by researchers from Duke L Jniversity in the US found that cutting one sdaily intake of calories could slow down biological aging, which means you might be able to hang on to your youthful looks a little longer. Previous research has shown that calorie restrictions slow aging in worms, flies and mice. So researchers wondered if it could have the same effect on people.To find out, Daniel Belsky and her teamTo find out, Daniel Belsky and her team examined data from a study by the National Institute on Aging, based in the US, which involved 220 people. During the two-year study, 145 people in the restriction group cut their calorie intake by 25 percent. Meanwhile, 75 peoplein the control group maintained their normal diets.At the start of the study, the two groups had no difference inbiological age.The average participant was 38 years old, with a biological age of 37. However, after each 12- month period, participants in the restriction group saw an increase in biological age by an average of 0.1 1years. Meanwhile, those in the control group saw a rise by an average of 0.71 years. The researchers believe the difference between these groups shows that cutting calories does slow biological aging. Although they didn't explain the reason behind this, researchers at Brigham Young University in the US provided an explanation after they carried out a similar study on mice. Theybelieve fewer Calories slow down a mechanism in cells called the ribosome (核糖体)，at least in mice. The mechanism is responsible for making vital proteins in cells,but with fewer calories it slows down, giving it more time to repair itself, The ribosome is complex like a car, and itneeds to replace the parts that wearout the fastest from time to time, according to John Price, a biochemistry professor at Brigham Young University.“When tires wear out, you don't throw the whole car away and buy new ones. It's easier to replace the tires," Price told VOA. But this doesn't mean that people who want to look younger should start skipping meals, especially given the study's early stage. Proper nutrition is important, Price explained. “Food isn't just material to be burned -it's a signal that tells our body and cells how to respond,"he told Science Daily.

The purpose of the research was ().

A.test the influence of calorie restrictions on aging.

B.explain why people have to maintain a normal diet.

C.find the most efficient way to control calorie intake.

D.invent technology that keeps people young and healthy.

Which of the following statements is TRUE about the experiment ()?

A.The biological age of people in the control group increased more than those in the restriction group.

B.Some participants were asked to double the amount of food they ate.

C.Flies and mice were used to compare the results of the human test with.

D.AlI the participants were of the same biological age at the start.

According to John Price, ().

A.a higher level of calorie intake meansmore healthy proteins.

B.reducing calorie intake could allow the ribosome to repair itself better.

C.the fewer calories one takes in, the better the ribosome works.

D.the ribosome is an important cell that controls the aging process.