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【简答题】

Plastic is everywhere because plastic is an extremely useful material. It is cheap, strong and lightweight. What’s more, it can take on nearly any form or shape, from soft and stretchy (有弹性的) to hard and glasslike.
Plastic, however, is far from perfect. It may even be bad for us. Studies now suggest that poisonous chemicals can get out of some types of plastic, get into our bodies, and cause a variety of health problems, including cancer, birth defects and attention deficit hyperactivity disorder (注意缺陷障碍).
Two types of chemicals in particular have raised special concern lately. They are called phthalates (邻苯二甲酸盐) and Bisphenol-A (二酚基丙烷), BPA for short. Not all plastic products contain them. But the ones that do are surrounded by controversy (争议). That’s because experts disagree on how erous these chemicals are.
Plastic is a single word, but plastic isn’t just one thing. What all plastics share in common are plasticizers -- special chemicals that allow the material to be changed into nearly any shape or texture. Plasticizers (塑化剂) are added to plastic during the manufacturing process.
Phthalates and BPA are two types of plasticizers that work in different ways. Phthalates add softness to things like shampoo bottles, raincoats and rubber. They are also used in perfumes and makeup. BPA, on the other hand, gives a hard, clear, almost glasslike feel to products such as infant bottles. BPA also appears in food and soda cans, DVDs and other unexpected places.
How do these chemicals get into us? When plastic is heated in the microwave or dishwasher, chewed on or scratched, the chemicals can seep (渗透) out of the plastic. Even though we can’t see them, we eat them, drink them and breathe them in.
Scientists and parents are especially worried about young children, who tend to chew on everything, including plastic.Dozens of countries, including the European Union, Japan, Canada and Mexico have already banned phthalates from products made for children younger than three. California and Washington have done the same. And a number of other states are considering similar rules. As for BPA, Canada became the first country to ban the chemical from baby bottles. A dozen states are considering it.
小题1:What can we know about the plastic from the first paragraph?A.Its characters and effects.B.Its wide use and bad points.C.Its importance and chemicals.D.Its popularity and advantages.小题2:Which of the following products contains BPA?A.A soft plastic cup.B.A pencil eraser.C.A baby milk bottle.D.A new perfume.小题3:Phthalates and BPA can get into us __________. A.through mouth or noseB.through blood transfusionC.by feeling plastic productsD.by heating in the microwave小题4: What is the passage mainly about?A.A new ban on plastic products.B.Problems caused by the plastic.C.Good points of the plastic.D.The use of plasticizers.

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举一反三

【单选题】甲酸盐钻井液的配套处理剂几乎都是 () 。

A.
油溶性的
B.
水溶性的
C.
不溶于油和水的
D.
酸溶性的

【单选题】下列为苯甲酸盐的鉴别方法是 ( )

A.
取供试品的中性溶液,滴加三氯化铁试液,即生成赭色沉淀;再加稀盐酸,变为白色沉淀
B.
加 0.1 mol/L 亚硝酸钠溶液数滴,滴加碱性 β - 萘酚试液数滴,生成由橙黄到猩红色沉淀
C.
取供试品的中性溶液,加醋酸氧铀锌试液,即生成黄色沉淀
D.
取供试品少 量,置试管中,加等量的二氧化锰,混匀,加硫酸湿润,缓缓加热,产生的气体能使用水湿润的碘化钾淀粉试纸显蓝色