The destruction of habitats（栖息地）all over the world is the primary reason species are becoming extinct（灭绝）or endangered. Houses, highways, dams, industrial buildings, and ever-spreading farms now dominate _____（21）formerly occupied by forests, deserts, and wetlands. _____（22）the beginning of European settlement in America, _____（23）, over 65,000,000 acres of wetlands have been drained. One million acres alone vanished _____（24）1985 and 1995.Habitat destruction can be _____（25）or it can be subtle, occurring over a _____（26）period of time without being noticed. _____（27）such as sewage from cities and chemical runoff from farms, can change the _____（28）and quantity of water in streams and rivers. To _____（29）living in a delicately balanced habitat, this disturbance can be as _____（30）as the clear-cutting of a rainforest._____（31）remaining habitats are carved into smaller and smaller pockets or islands, remaining species are forced to exist in these _____（32）areas, which causes further habitat _____（33）.These species become less adaptable to environmental _____（34）; in fact, they become _____（35）endangered. Scientists believe that when a habitat is cut by 90%, one-half of its plants, animals and insects will become extinct.26._____.
A、long
B、short
C、happy
D、sad
【正确答案】：A
【题目解析】：理解判断题。前文提到栖息地的破坏是明显的或者是微妙的，即可能很长时间其变化都没有被注意到。a long period表示“很长一段时间”，故选A。
