问题 问答题

亚里士多德认为:重的物体比轻的物体下落得快.如果亚里士多德的观点正确,即物体跃重就一定下落得越快,那么将一个重物体和一个轻物体拴在一起让让它们下落,应比它们单独下落得更快.为了证实这一观点是否正确,某学校实验小组的同学在教学楼上做了以下实验:先后让三个物体从同一高度释放后都下落到同一水平面上,经过多次测量,得到了下表数据:

实验序号123
物体小石头羽毛球和羽毛球拴在一起的小石头
质量(g)22628
下落时间(s)1.452.431.65
(1)由上面的实验,选取第______次和第______次实验数据进行对比(填实验序号),可以说明亚里士多德的观点是错误的;

(2)为什么要选择这两次实验数据?

答案

(1)亚里士多德认为重的物体下落快,结果1和3相比较,3比1重,但同时从相同的高度落下,3所用的时间更长,所以3更慢.从而说明亚里士多德是错误的.

(2)答:因为仅将这两组数据相比较,得出重的物体下落得慢这个结论,可以有力地推翻亚里士多德的结论.所以选择这两组数据.

多项选择题
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An Australian man who has been donating his extremely rare kind of blood for 56 years has saved the lives of more than two million babies.

James Harrison has an antibody in his plasma that stops babies dying from Rhesus disease, a form of severe anaemia. He has enabled countless mothers to give birth to healthy babies, including his own daughter, Tracey, who had a healthy son thanks to her father's blood.

Mr. Harrison has been giving blood every few weeks since he was 18 years old and has now racked up a total of 984 donations. When he started donating, his blood was deemed so special that his life was insured for one million Australian dollars.

He was also nicknamed the “man with the golden arm” or the “man in two million”. He said: “I've never thought about stopping. Never.” He made a pledge to be a donor aged 14 after undergoing major chest surgery in which he needed 13 litres of blood. “I was in hospital for three months,” he said. “The blood I received saved my life so I made a pledge to give blood when I was 18.”

Just after he started donating he was found to have the rare and life-saving antibody in his blood. At the time, thousands of babies in Australia were dying each year of Rhesus disease. Other newborns suffered permanent brain damage because of the condition. The disease creates an incompatibility between the mother's blood and her unborn baby's blood. It stems from one having Rh-positive blood and the other Rh-negative.

His blood has since led to the development of a vaccine called Anti-D. After his blood type was discovered, Mr. Harrison volunteered to undergo a series of tests to help develop the Anti-D vaccine. “They insured me for a million dollars so I knew my wife Barbara would be taken care of,” he said. “I wasn't scared. I was glad to help. I had to sign every form going and basically sign my life away.”

Mr. Harrison is Rh-negative and was given injections of Rh-positive blood. It was found his plasma could treat the condition and since then it has been given to hundreds of thousands of women. It has also been given to babies after they are born to stop them developing the disease.

It is estimated he has helped save 2.2 million babies so far. Mr. Harrison is still donating every few weeks now.

小题1:How old is James Harrison?

A.56

B.70

C.74

D.78小题2:What does the underlined phrase “two million” refer to?

A.babies

B.mothers

C.dollars

D.all of the above小题3:   Why did James decide to donate his blood? Because _____.

A.his daughter asked him to help her son

B.he has a golden arm worth a million dollars

C.a vaccine called Anti-D is to be developed

D.someone else’s blood saved his life小题4:The sentence “The disease creates an incompatibility between the mother's blood and her unborn baby's blood” (underlined in Paragraph 5) suggests that _____.

A.babies suffer permanent brain damage before born

B.the mother and the baby have different types of blood

C.Rhesus disease contributes to permanent brain damage

D.all the patients have a rare antibody in their blood小题5:   What can we infer from the sixth paragraph?

A.Some of the tests to develop the vaccine are dangerous.

B.His wife Barbara needed to be taken care of badly then.

C.Mr. Harrison was glad to help develop a new vaccine.

D.His blood type was accidentally discovered after tests.