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

听力原文：

    Dogs, man’s best friends, have a clear strategy for dealing with angry owners—they look away.

    （19） New research shows that dogs limit their eye contact with angry humans. The scientists suggest this may be an attempt to calm humans down. This behavior may have evolved as dogs gradually learned they could benefit from avoiding conflicts with humans.

    To conduct the tests, the University of Helsinki researchers trained 31 dogs to rest in front of a video screen. Facial photos of dogs and humans were displayed on the screen for 1.5 seconds. They showed threatening, pleasant and neutral expressions. Nearby cameras tracked the dogs’ eye movements.

    Dogs in the study looked most at the eyes of humans and other dogs to sense their emotions. （20）When dogs looked at expressions of angry dogs, their eyes rested more on the mouth, perhaps to interpret the threatening expressions. And when looking at angry humans, they tended to turn away their gaze.

    Dogs may have learned to detect threat signs from humans and respond by trying to make peace, according to researcher Sanni Somppi. Avoiding conflicts may have helped dogs develop better bonds with humans.

    The researchers also note that dogs scan faces as a whole to sense how people are feeling, instead of focusing on a given feature. （21）They suggest this indicates that dogs aren’t sensing emotions from a single feature, but piecing together information from all facial features just as humans do.

19. What do dogs do when they are faced with angry humans?

解析：A。本题目为细节题。问题为：面对愤怒的人类，狗会怎么做？出题位置为第二段首句。根据原文“New research shows that dogs limit their eye contact with angry humans.”，可见最新研究表明狗会避免与愤怒的人类进行眼神接触。选项A）They avoid looking at them意为“它们避免看他们（生气的人类）”，与该信息一致，且looking at 与limit their eye contact为同义替换。