At first, the grains of rice that Ingo Potrykus held in his fingers did not seem at all _________, but inside, these grains were not white, as ordinary rice is, but a very pale yellow — thanks to beta-carotene (胡萝卜素), a building block for vitamin A.
For more than a decade Potrykus had _________ creating a golden rice that could improve the lives of millions of the poorest people in the world, strengthening their eyesight and their _________ disease.
_________ imagining golden rice was one thing and creating one quite another. Year after year, Potrykus and his colleagues ran into one _________ after another until success finally came in the spring of 1999.
At that point, he tackled an even greater challenge. The golden grains _________ pieces of DNA borrowed from bacteria and flowers. It was what some would call Frankenfood, a product of genetic engineering. As such, it _________ a web of hopes und fears.
The debate began the moment genetically engineered crops (GM crops) were first sold in the 1990s, and it has _________ ever since. First to start major protests against biotechnology were European environmentalists and consumer-advocacy groups. They were soon followed by their U.S. counterparts (相对应的人事物).
The hostility is _________. Most of the GM crops __________ so far have been developed to produce a plant that is not harmed by chemicals used to kill weeds (杂草) in the fields. These genetically engineered crops are often sold by the same large, multinational corporations that __________ the weed-killing chemicals that farmers spray on their fields. Consumers have become suspicious (怀疑的).
The benefits did seem small __________ golden rice was developed. It is the first strong example of a GM crop that may __________ not just the farmers who grow it but also the consumers who eat it. In this case, those include at least a million children who die every year because they are weakened by vitamin-A deficiency (缺乏) and an additional 350,000 who go blind.
Many people __________ poverty and hunger look at golden rice and see it as evidence that GM crops can be made to serve the greater public good. They see a critical role for GM crops in feeding the world’s ever-increasing population. As former U.S. President Jimmy Carter put it, “Responsible biotechnology is not the enemy; __________ is.”
1．| A．typical | B．special | C．local | D．white |
2．| A．dreamed of | B．come in handy | C．been reminded of | D．broken up |
3．| A．attempt at | B．effort to | C．resistance to | D．majority of |
4．5．| A．surprise | B．obstacle | C．norm | D．opposition |
6．| A．achieved | B．stressed | C．overlooked | D．contained |
7．| A．was caught in | B．was alive with | C．be conscious of | D．was honored by |
8．| A．announced | B．maintained | C．escalated | D．applied |
9．| A．brilliant | B．understandable | C．discharged | D．rewarding |
10．| A．introduced | B．reminded | C．respected | D．overlooked |
11．| A．toss and turn | B．give and take | C．produce and sell | D．demand and supply |
12．| A．until | B．after | C．although | D．when |
13．| A．feature | B．mark | C．build | D．benefit |
14．| A．worried about | B．ashamed of | C．filled with | D．admired for |
15．| A．terror | B．misery | C．starvation | D．crisis |
+SO
+4H+=2SO2↑+S↓+2H2O
+16H+=10CO2↑+2Mn2++8H2O
。向
的
或
时(忽略溶液体积的变化)，各微粒的分布系数
随溶液
变化的曲线如图所示：
，X为
、
或
]
、
、
)
滴定
至恰好生成
，可选甲基橙做指示剂
的水解常数
的数量级为
既有还原性又有氧化性，探究其能否实现
或
的转化。
既易被氧化也易被还原，因此水溶液中无法生成水合
为白色固体，难溶于水，可溶于
较大的溶液生成
，也可溶于氨水生成
(无色)。
的反应
溶液
溶液
的价层电子排布式为
检验的因素。写出ⅲ中反应的离子方程式：
。
；
稀硫酸
。补全d中反应的离子方程式：
_______
_______。
，下列方法合理的是_______。
可用于
的路线为“
”，写出没有颜色变化反应的化学方程式：
的氧化性
溶液中通
溶液
发生反应所致，猜想正确。
氧化性，与
，
) 
的中点为M，过点M任作两弦
，弦
与
分别交
的中点；
且
，
是定义在
上的一系列函数，满足
.
的解析式.
为定义在
.
的方程
有且仅有一个实根，求实数
的取值范围. 
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