Scientists recently examined studies on dog intelligence and compared them with research into the minds of other intelligent animals. The researchers found that dogs are among the more intelligent carnivores (食肉动物), social hunters and domestic animals, but that their intelligence does not【C1】________ other intelligent animals in any of those categories. Though a significant body of research has examined dog cognition【C2】_____, the authors of this new study found little to warrant the【C3】_____of work that has been devoted to the topic.

Stephen Lea, lead author of the new study, argues that many researchers seem to have designed their studies to【C4】_____how clever dogs are, rather than simply to study dogs’ brains. Lea and a colleague examined more than 300 studies of dog cognition, comparing the studies’ results with those from research into other animals. The researchers made specific comparisons between the different species in different categories of intelligence. These comparisons【C5】__that dogs are intelligent, but their intelligence is not as【C6】_____as some researchers might have believed.

In many areas, though, comparisons were not possible. For example, the researchers noted that both dogs and cats are known to be able to recognize and【C7】_____human voices. But the investigators could not find any data to indicate which species can remember a greater number of【C8】__human voices, so it was impossible to compare the two on that front. However, not all researchers agree【C9】__with the findings of this study. Zachary Silver, an American researcher, believes the authors of the new study【C10】_____the idea that an excessive amount of research has been devoted to dogs, as the field of dog cognition is young, and there is much to be learned about how dogs think.

A) affirmed I) overstated

B) approximately J) pledge

C) completely K) previously

D) differentiate L) prospective

E) distinct M) prove

F) domain N) surpass

G) formidable O) volume

H) outperformed

【C7】