2014年职称英语考试-阅读理解强化习题(15)_职称英语阅读理解

2014年职称英语考试-阅读理解强化习题(15)

　　Spacing in Animals

　　Flight Distance

　　Any observant person has noticed that a wild animal will allow a man or other potential enemy to approach only up to a given distance before it flees. Flight distance is the terms used for this interspecies spacing. As a general rule, there is a positive relationship between the size of an animal and its flight distancethe larger the animal, the greater the distance it must keep between itself and the enemy. An antelope will flee when the enemy is as much as five hundred yards away. The wall lizards flight distance, on the other hand is about six feet. Flight is the basic means of survival for mobile creatures.

　　Critical Distance

　　Critical distance apparently is present wherever and whenever there is a flight reaction. Critical distance includes the narrow zone separating flight distance from attack distance. A lion in a zoo will flee from an approaching man until it meets a barrier that it cannot overcome. If the man continues the approach, he soon penetrates the lions critical distance, at which point the cornered lion reverses direction and begins slowly to stalk the man.

　　Social Distance

　　Social animals need to stay in touch with each other. Loss of contact with the group can be fatal for a variety of reasons including exposure to enemies. Social distance is not simply the distance at which an animal will lose contact with his groupthat is, the distance at which it can no longer see, hear, or smell the groupit is rather a psychological distance, one at which the animal apparently begins to feel anxious when he exceeds its limits. We can think of it as a hidden band that contains the group.