Intelligence, it turns out (第5题答案为C), is a high-priced option. It takes more upkeep, burns more fuel and is slow off (第6题答案为A)the starting line because it depends on learning — a gradual  (第7题答案为D)process— instead of instinct. Plenty of other species are able to learn, and one of the things they’ve apparently learned is when to stop. (第8题答案为C)

Is there an adaptive value to limited(第9题答案为B) intelligence? That’s the question behind this new research. I like it. Instead of casting a wistful glance backward (第10题答案为D) at all the species we’ve left in the dust I.Q.-wise, it implicitly asks what the real costs (第11题答案为D) of our own intelligence might be. This is on (第12题答案为B) the mind of every animal I’ve ever met.

（Every chicken that looks at you sideways — which is how they all look at you — is really saying what Thoreau said less succinctly: you are endeavoring to solve the problem of a livelihood by a formula more complicated than the problem itself. Thoreau himself would not dispute that he was hoping to recover the chicken’s point of view. He went to Walden Pond “to remember well his ignorance.”）

Research on animal intelligence also makes me wonder what experiments animals would perform (第13题答案为C) on humans if they had the chance. Every cat with an owner, for instance(第14题答案为D), is running a small-scale study in operant conditioning. I believe that if(第15题答案为A) animals ran the labs, they would test us to determine(第16题答案为C) the limits of our patience, our faithfulness, our memory for terrain. They would try to decide what intelligence in humans is really for(第17题答案为B), not merely how much of it there is.Above all(第18题答案为A), they would hope to study a fundamental (第19题答案为A) question: Are humans actually aware of the world they live in? So far (第20题答案为C) the results are inconclusive.