81. It can be inferred from the text that animal emotions ____.

1. originate from natural evolution
2. develop faster in social encounters
3. remain uncertain until we are sure
4. are as rich and deep as human emotions

82. It is implied by the ideas of evolutionary continuity that ____.

1. the lifestyle of different species is continuous in evolution
2. there is no clear border between human beings and animals
3. all species depend on complex social interactions to survive
4. more similarities among species have been evolved than dissimilarities

83. Some people maintain a scientific skepticism because they ____.

1. fail to realize what uncertainty really means to science
2. are uncertain about whether animals have emotions
3. prefer to put off whatever they do in science
4. ignore the nature of scientific research

84. According to Henry Pollack, uncertainty ____.

1. hinders scientific progress
2. catalyzes creativity in science
3. means the absence of certainty
4. accounts for all our decisions in life

85. By citing the example of the response to his questions, the author shows that ____.

1. people usually prefer positive questions to negative ones
2. whether dogs have feelings is a desirable question to ask
3. whether dogs don't have feelings is a silly question to ask
4. human behavior can serve as a guide to study animal feelings

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