Question 19 is based on the passage you have just heard.

Passage Two

听力原文

        There’s an endless amount of scientific data proving that dogs can develop strong bonds with their owners. People aren’t kidding when they say they “love” their dog or their dog “loves” them. (19) But we’re rather ignorant about the nature of the relationships that form between dogs. In an effort to understand the matter further, I spoke with Dr. Marc Bekoff a researcher and former professor of animal behavior. (20) The doctor’s response to the question of whether or not dogs can fall in love like humans do was a straight “of course”. He went on to say that if love is defined as a long-term commitment—meaning dogs seek one another out when they’re apart, they’re happy when they’re reunited, they protect one another, they feed one another, they raise their children together—then, of course, dogs love each other. Now our furry friends don’t really experience “romantic” love, like in the movies, but they can form deep and lasting bonds with their fellow dogs as well as humans. (21) In fact, evidence shows that most dogs stay with one partner their whole lives. In actuality, love between dogs can be even more intimate than human relationships. When they interact, they aren’t afraid to smell each other and will express themselves clearly and honestly. Once again, it seems we have a lot to learn from dogs.

19. What does the passage say we don’t know much about?

解析：B。录音开头指出，人们很难意识到狗与狗之间关系的本质。题干中的don’t know much about与原文中的ignorant about属于同义替换，而B项中The nature of relationships between dogs与原文表述一致，因此B项正确。A项在原文中未提及，故排除。C项利用录音中People和“love” their dogs作干扰，但原文并非讨论人类爱狗的原因，故排除。D项利用录音中的bonds with作干扰，但同样并非是录音讨论的话题，故排除。