The destruction of habitats(栖息地)all over the world is the primar

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 fromfarms,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． 第34题的答案是（ ）
A、improvements
B、Changes
C、protection
D、development
【正确答案】：B
【题目解析】：第34题的答案是B，即Changes（变化）。 在这段文本中，第34题所在的句子是“These species become less adaptable to environmental changes; in fact, they become increasingly endangered.”（这些物种对环境变化的适应能力越来越差；事实上，它们变得越来越濒危。）这句话明确提到了“环境变化”（environmental changes），因此B选项“Changes”是最符合语境的答案。 其他选项如A选项“improvements”（改进）、C选项“protection”（保护）和D选项“development”（发展）与句意不符。文中并未提到环境有“改进”或“保护”，而且“发展”一词通常指的是积极的变化，而这里强调的是物种对环境变化的适应能力下降，因此D选项也不合适。 因此，正确答案是B，“Changes”。