阅读下列短文,从每题所给的A、B、C、D四个选项中选出最佳选项。
A
Stephen Hawking said, “Scientists have become the bearers of the torch of discovery in our quest（探求） for knowledge.” Given below are some of them:
Headlie Taylor （July 7, 1883—March 22, 1957）
Headlie Taylor was hardly educated but had a good mind. With hard work and creativity, he taught himself engineering. He built a machine that could not only collect grains from standing crops, but also from damaged or fallen ones, thus saving grains that would otherwise be lost. This machine, the Header Harvester, also cut the crop heads instead of pulling them out.
John Cornforth （September 7, 1917—December 8, 2013）
John Cornforth completely lost his hearing in his teens. However, his determination led him to become one of the greatest scientists of his day. Dr Cornforth studied the enzymes（酶） that caused changes in organic compounds（有机物） and went on to reduce the amount of cholesterol（胆固醇）. He won the Nobel Prize in Chemistry in 1975.
David Warren （March 20, 1925—July 19, 2010）
The Black Box is an electronic instrument that records every voice in the cabin. In case of an accident, the readings from it can be used to determine the series of events that led to the air crash. Dr Warren came up with this idea of recording flight data following a strange airplane accident in Australia. Though in the beginning his ideas weren't paid attention to, they soon took the world by storm.
Graeme Clark （August 16, 1935—）
Growing up, Graeme Clark watched his deaf father struggle with communication. This inspired him to create a device that could be put into a person's inner ear, which would record sound. Years of careful research finally resulted in the Bionic Ear, which provides deaf persons with the sense of hearing.
21. Whose achievement directly benefits farmers?
A. Headlie Taylor's. B. John Cornforth's. C. David Warren's. D. Graeme Clark's.
22. What can we learn about John Cornforth?
A. He was born totally deaf.
B. His work was recognized when he was alive.
C. He was the greatest scientist of his day.
D. His research wasn't well accepted at first.
23. What directly led Graeme Clark to work on the Bionic Ear?
A. His experience of losing hearing. B. His interest in doing research.
C. His father's encouragement. D. His father's suffering.
