题目

Habits, whether good or bad, are gradually formed．When a person does a certain thing again, he is driven by some unseen force to do the same thing repeatedly, then a habit is formed．Once a habit is formed, it is difficult, and sometimes impossible, to get rid of．It is therefore so important that we should pay great attention to the formation of habits．Children often form bad habits, some of which remain with them as long as they live．Older persons also form bad habits lasting as long as they live, and sometimes become ruined by bad habits．        There are other habits which,我国某地区的植被多呈斑块分布的特征。在自然降水条件下，该地区结皮斑块产生的径流、侵蚀产物、有机质、氮及溶解养分中均大量被位于下坡向的灌丛斑块截获。下图为该地区植被呈斑块状分布的山坡。读图完成下列各题。1.形成a处堆积物的地质作用最可能是A.风力作用 B.流水作用C.冰川作用 D.风化作用2.b处植被的作用主要是A.增加湿度和径流 B.减小风速和沙尘C.阻止冰川和固沙 D.拦截径流和泥沙3.从植被分布的格局看，该地区最可能位于A.干旱半干旱地区 B.沿海地区C.湿润地区 D.热带地区