题型:阅读理解 题类:模拟题 难易度:普通
上海市松江区2019届高三英语二模试卷(音频暂未更新)
Being able to land safely is a critically important skill for all flying animals. Comparatively speaking, ground living animals face no particular challenge when they need to stop running or crawling, while flying animals move at much higher speed, and they must be careful about how they land. Hitting the ground, or even water, at full flight speed would be quite dangerous. Before touching down, they must decrease their speed in order to land safely. Both bats and birds have mastered the skill of landing, but these two types of flyers go about it quite differently.
In the past it was believed that, in terms of flying mechanics, there was little difference between bats and birds. This belief was based only on assumption, however, because for years nobody had actually studied in detail how bats move their wings. In recent years, though, researchers have discovered a number of interesting facts about bat flight. Bats are built differently from birds, and their wings are made up of both their front and hind limbs (肢体). This makes coordinating (协调) their limbs more difficult for bats and, as a result, they are not very good at flying over longer distances. However, they are much better at the ability to adjust themselves: a bat can quickly change its direction of flight or completely reverse it, something a bird cannot easily do.
Another interesting characteristic of bat flight is the way in which bats land-upside down! Unlike birds which touch down on the ground or on tree branches, bats can be observed flying around and then suddenly hanging upside down from an object overhead. One downside to this landing routine is that the bats often land with some force, which probably causes pain. However, not all bats hit their landing spots with the same speed and force; these will vary depending on the area where a bat species makes its home. For example, a cave bat, which regularly lives on a hard stone ceiling, is more careful about its landing preparation than a bat more accustomed to landing in leafy treetops.
试题篮