As a child, the Russian writer Leo Tolstoy was once challenged by his older brother to remain standing in a corner until he could stop thinking of a white bear. That is, he was challenged to engage in .

the correct answer is individualism and exchange. at this stage, children begin to question the rules, because they can see that there is more than one side to them. different individuals have different viewpoints. they won't be able to reach this stage because of ignorance, a lack of ethics or personal biases. that is because people with that characteristiscs are not able to distinguish what is good or what is bad and they can't pursue their individual interests.

hygrometers and hair thermometers (often found as part of hygrometers/psychrometers) can be used to measure humidity. barometers are used to measure atmospheric pressure, while anemometers are used to measure wind speed. so the 2nd and 4th choices should be the correct answers.