"When I grow up，I want to be a runner." These words are spoken by thousands of Kenyan children.50 percent of the Kenyan top runners are members of Kalenjin，one minority race of the country.They make up less than two percent of Kenya's population.This fact has puzzled sports scientists.They have spent considerable time and effort trying to answer one question：What enables the Kalenjin people to run so fast？
   Although the question seems simple，finding the answer has proven to be difficult and controversial （有爭議的）.A team of Danish sports scientists spent 18 months and discovered the Kalenjins had remarkably slow heart rates even when running long distances.The Kalenjins live in high-elevation（高海拔）villages in the Rift Valley in western Kenya.People living at high elevations produce more red blood cells，which aid in the transport of oxygen throughout the body.Because the air is thinner and contains less oxygen at high elevations，the body produces more red blood cells.Scientists believe there is a connection between increased red blood cells and low heart rates and that both may enable high-altitude athletes to outperform those who train at low altitudes.The Danish scientists also studied the bodies of the Kalenjins and compared them to those of the Danes.They found that the Kalenjins have longer "birdlike" legs.The Kalenjins also have lower body mass indexes（a measure of body fat based on weight and height）and shorter bodies than Danish people.
   As a result of the Danish study，some scientists made the conclusion that the Kalenjins possess what is called a "speed gene（基因）".However，Kenyan runners were offended by this conclusion.They owed their success to hard work and endless hours of training.
   Although the controversy over the "speed gene" remains unsolved，British runner Mo Farah's experience offers an interesting perspective on the subject.In 2005，he realized he wasn't meeting his potential as a runner.A group of Kenyan runners were training in England then.After he accidentally observed the Kenyans' strict training routines and dedication to their sport，Farah said it was like a switch had been turned on in his jye.aiad.He began eating healthy foods，going to bed early，and training harder than he had ever trained in his life.As a result，Farah's running career exploded.He has won seven world and Olympic titles in the 5000 m and regularly beats Kenya's top runners!
   Farah's story proves what Kenyans have known all along.Regardless of genetics，their success would not be possible without hard work，dedication，sacrifice，and mental toughness.Their "secret" is simple.Train hard，run fast and never give up.

（1）What interested the sports scientists？

B

B

A．Kenyan sports history.
B．Kanlenjins' running ability.
C．Kanlenjins' training methods.
D．Kenyans' enthusiasm for sport.
（2）According to Danish scientists，what leads to the Kanlenjins' success？

A

A

A．Physical condition.
B．Hard training.
C．Healthy lifestyle.
D．Strong will.
（3）What did Kenyan runners think of Danish research result？

C

C

A．Satisfactory.
B．Typical.
C．Unacceptable.
D．Important.
（4）Why is Mo Farah's story mentioned in the passage？

C

C

A．To show running methods count.
B．To encourage British athletes.
C．To prove effort pays off.
D．To support gene theory.