[判断题]柴油机喷油过迟使汽缸顶部在燃烧前已积累了较多柴油，使开始燃烧-我要搜题网

[不定项选择题]共用题干 The World's Best-Selling Medicine
Since ancient times,people all over the world have used willow to stop pain. The willow tree contains salicylic acid（水杨酸）.This stops pain, but there is one problem. Salicylic acid also hurts the stomach. In 1853,a French scientist made a mixture from willow that did not hurt the stomach.
However,his mixture was difficult to make,and he did not try to produce or sell it.
In 1897,in Germany,Felix Hoffmann also made a mixture with salicylic acid. He tried it himself first and then gave it to his father because his father was old and in a lot of pain.
His father's pain went away,and the mixture did not hurt his stomach.
Hoffmann worked for Bayer,a German company. He showed his new drug to his manager,who tested the drug and found that it worked well.Bayer decided to make the drug.
They called it aspirin and put the Bayer name on every pill.
Aspirin was an immediate success. Almost everyone has pain of some kind,so aspirin answered a true need. Aspirin was cheap,easy to take,and effective. It also lowered fevers.
Aspirin was a wonder drug.
At first,Bayer sold the drug through doctors,who then sold it to their patients. In 1915,the company started to sell aspirin in drugstores.In the United States,Bayer had a patent（专利权）on the drug. Other companies could make similar products and sell them in other countries,but only bayer could make and sell aspirin in the United States.In time,Bayer could no longer own the name aspirin in the United States. Other companies could make it there,too.However,Bayer aspirin was the most well known,and for many years,it was the market leader.
By the 1950s,new painkillers were on the market. Aspirin was no longer the only way to treat pain and reduce fever. Bayer and other companies looked for other drugs to make.However,in the l970s they got a surprise. Doctors noticed that patients who were taking aspirin had fewer heart attacks than other people. A British researcher named John Vane found the reason aspirin helped to prevent heart attacks.In 1982,he won the Nobel prize for his research. Doctors started to tell some of their patients to take aspirin every day to prevent heart attacks.It has made life better for the many people who take it. It has also made a lot of mon-ey for companies like Bayer that produce and sell it! Bayer started making aspirin because______.
A.it helped prevent heart attacks
B.other companies were making it
C.it worked well in stopping pain
D.the manager was a scientist

[判断题]柴油机喷油过迟使汽缸顶部在燃烧前已积累了较多柴油，使开始燃烧时间提前。活塞还未达上止点前，燃油的爆燃对活塞产生与其运动方向相反的压力波，使活塞与汽缸壁之间会产生粗暴的敲击声。( ) A.正确B.错误

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[判断题]柴油机喷油过迟使汽缸顶部在燃烧前已积累了较多柴油，使开始燃烧时间提前。活塞还未达上止点前，燃油的爆燃对活塞产生与其运动方向相反的压力波，使活塞与汽缸壁之间会产生粗暴的敲击声。( )
A.正确
B.错误