题目

甲、乙、丙、丁四种易溶于水的物质，分别由NH4＋、Ba2＋、Mg2＋、H＋、OH－、Cl－、HCO3－、SO42－中的不同阳离子和阴离子各一种组成。已知：①将甲溶液分别与其它三种物质的溶液混合，均有白色沉淀生成；② 0.1mol/L乙溶液中c（H＋）>0.1mol/L；③ 向丙溶液中滴入AgNO3溶液有不溶于稀HNO3的白色沉淀生成。下列结论不正确的是A. 甲溶液含有Ba2＋       B. 乙溶液含有SO42－C丙溶液含有Cl－        D.丁溶液含有Mg2＋ Coffee is one of the world's most widely-enjoyed drinks. Now, a new research suggests that if you drink enough coffee, it might help you avoid certain kinds of cancer.Dr. Mia Hashibe of the University of Utah School of Medicine was interested in the connection between coffee drinking and certain cancers of the head and neck. Researchers have looked into this before, but without reaching any firm conclusions. She said, "So this finding from our new study was quite a surprise. We didn't really have any expectation of which direction it could go into." To sort out the confusion, Hashibe and her assistants used statistical (统计学 ) techniques to, in effect, make one big study out of the earlier smaller studies. She explained,  "Thanks to the earlier studies, we have a lot more power than earlier studies that looked at this. And we included 4,000 cancer patients who have cancer of the mouth and throat. And then 9,000 controls, people who do not have cancer. 'Those studies--in Europe and the United States--found that people who drank a lot of coffee were less likely to develop cancers of the mouth and throat. "We saw a protective effect for drinking more than 4 cups of coffee per day," Hashibe said. "This was the 40 percent decrease in risk. We did not see the same effect for drinking three cups or less per day."Mia Hashibe said there was a weak connection between cancer risk and drinking coffee without caffeine. And she and her assistants found no proof that drinking tea provided the same protection as drinking Coffee. Their research is published in the journal Cancer Epidemiology, Biomarkers & Prevention.Hashibe says it is not clear how coffee might protect drinkers from certain cancers. "There are a few chemicals that are known to be antioxidants （抗氧化物）in coffee. So we are thinking perhaps they are playing some sort of protective role against several cancers."小题1:This passage is probably taken from __A．a literature bookB．a travel journalC．an old directoryD．a medical magazine小题2:Dr. Hashibe expected nothing of her research because __A．it was impossible to get the desired resultB．the research was much surprising in factC．no conclusions had been reached beforeD．the research team lacked faith in success小题3:Which of the following might have something to do with the protection against mouth cancer?A．Coffee without chemicals.B．Coffee without caffeine.C．Four cups of tea a day.D．Antioxidants in coffee.小题4:What do we know about Dr. Mia Hashibe and her research?A．She knew for sure how coffee may affect drinkers.B．She included 4,000 people without cancer in study.C．She found an effect for three cups of coffee a day.D．She based her research on several earlier studies.小题5:What would be the best title for the text?A．Drinking Coffee May Protect Some CancersB．Drinking Coffee May Prevent Some CancersC．Drinking Coffee May Cure Some CaneersD．Drinking Coffee May Cause Some Cancers