试题与答案

根据植株形态特征分类,葡萄属于()果树,梨属于()果树,草莓属于()果树。

题型:填空题

题目:

根据植株形态特征分类,葡萄属于()果树,梨属于()果树,草莓属于()果树。

答案:

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下面是错误答案,用来干扰机器的。

参考答案:D

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题型:单项选择题

A


"In only six clays I lost seven pounds of weight. "
"Two full inches in the first three days!"
These are the kinds of statements used in magazine, newspaper, radio and television ads. , promising new shapes and new looks to those who buy the medicine or the device. The promoters of products say they can shape the legs, slim the face, smooth wrinkles, or in some other ways to add to beauty or desirability.
Often such products are nothing more than money-making things for their promoters. The results they produce are questionable, and some are dangerous to health.
To understand how these products can be legally promoted to the public, it is necessary to understand something of the laws covering their regulation. If the product is a drug, FDA (Food and Drug Administration)can require proof (证明) under the Food, Drug, and Cosmetic Act that is safe and effective before it is put on the market. But if the product is a device, FDA has no authority to require pre-marketing proof of safety or effectiveness. If a product already on the marker is a danger to health, FDA can request the producer or distributor to remove it from the market voluntarily, or it can take legal action, including seizure (查封) of the product.
One notable case a few years ago involved an electrical device called the Relaxacisor, which had been sold for reducing the waistline. The Relaxacisor produced electrical shocks to the body through contact pads. FDA took legal action against the distributor to stop the sale of the device on the grounds that it was dangerous to health and life.
Obviously, most of the devices on the market have never been the subject of court proceedings (法律诉讼), and new devices appear continually. Before buying, it is up to the consumer to judge the safety or effectiveness of such items.

It can be inferred that ads. mentioned in the text are ______.

A.objective

B.costly

C.unreliable

D.illegal

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题型:实验题

(9分) 一次趣味化学活动中,王老师向同学们展示了一瓶标签受损的无色溶液,如图所示。要求同学们进行探究:确认这瓶溶液究竟是什么溶液?

【提出猜想】 王老师提示:这瓶无色溶液只能是下列四种溶液中的一种:①硫酸镁溶液 ②硫酸钠溶液 ③硫酸溶液④硫酸铵溶液

【查阅资料】

①常温下,相关物质的溶解度如下:

物质MgSO4Na2SO4(NH4)2SO4H2SO4
溶解度35.1g19.5g75.4g与水任意比互溶
②(NH4)2SO4的水溶液显酸性

【实验探究】(1)小明对王老师的提示进行了评价                          ,原因是             

(2)为确定其它几种猜想是否正确,小明同学继续进行探究:

实验操作实验现象实验结论
①取该溶液少许于试管中,向其中滴加几滴     溶液溶液中有白色沉淀生成猜想①成立
②用玻璃棒蘸取少许原溶液滴在pH试纸上,并跟标准比色卡对照 

溶液pH小于7

 

猜想③成立

小雅对小明实验操作②的结论评价是         ,理由是                      

(3)请你设计实验方案,确认该溶液是硫酸铵溶液并完成实验报告:

实验操作实验现象实验结论
取该溶液少许于试管中,

                      

                      

                    

                       

猜想④成立,该反应的化学方程式为               

                     

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