题干

银器的保护主要是维持它的原貌,对于轻微腐蚀蒙有硫化银的银器,可将其和铝片一起接触浸泡在稀NaOH溶液中,经一定时间污迹消失,取出后用水洗于净,再用软布或棉团擦光.有关叙述正确的是(  )

A:溶液中的OH离子向正极移动

B:在银表面上的反应为:Ag2S+2e═2Ag+S2

C:反应后容易的pH增大

D:在铝表面的反应为:Al+4OH﹣3e═AlO2+2H2O

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B,D

同类题1

Directions: For each blank in the following passage there are four words or phrases marked A, B, C and D. Fill in each blank with the word or phrase that best fits the context.

           If you studied pictures that ancient people left on rock walls and you tried to determine their meaning, you would not detect interest in romance among the artists. 1, you would see plenty of animals with people running after them. Life for ancient people’s earned to center on hunting and gathering wild foods for meals.

           In modern times, when food is available in grocery stores, finding love is more 2 in people’s lives. The 3is all around us. It is easy to prepare a list of modern stories having to do with love. An endless number of books and movies qualify as love stories in popular culture.

           Researchers are studying whether love, a highly valued emotional state, can be 4. They ask, what is love? Toothpaste companies want us to think attraction is all about clean teeth, but clean teeth go only so far. Scientists wonder how much the brain gets involved. You have probably heard that opposites attract but that 5attract, too. One thing is certain: The truth about love is not yet set in stone.

First Impression

           To help determine the 6 of attraction, researchers paired 164 college classmates and had them talk for 3, 6 or 10 minutes so they could get a sense of each other’s individuality. Then students were asked to7what kind of relationship they were likely to build with their partners. After nine weeks, they reported what happened.

As it turned out, their 8judgments often held true. Students seemed to9at an early stage who would best fit into their lives.

The 10 Knows

           Scientists have also turned to nonhumans to increase understanding of attraction. Many animals give off pheromones — natural chemicals that can be detected by, and then can produce a response in, other animals of the same species. Pheromones can signal that an animal is either ready to fight or is feeling 11 to partnerships. In contrast, humans do not seem to be as 12 as other animals at detecting such chemicals. Smell, however, does seem to play a part in human attraction. Although we may not be aware of chemicals like pheromones consciously, we give and receive loads of information through smell in every interaction with other people.

Face Value

           Being fond of someone seems to have a number of factors, including seeing something we find attractive. Researchers had people judge faces for 13. The participants had 0.013 seconds to view each face, yet somehow they generally considered the images the same as people who had more time to study the same faces. The way we14attractiveness seem to be somewhat automatic.

When shown an attractive face and then words with good or bad associations, people responded to 15words faster after viewing an attractive face. Seeing something attractive seems to cause happy thinking.