-
-
>> 高等继续教育 / 教育社会学
-
佳题速递：
地西泮抗焦虑作用的主要部位药理学 Trees mainly serve man in three important ways: They provide him with wood and other products; they provide him shade; and they help to prevent droughts and floods.Unfortunately, in many parts of the world, man has not realized that the third of these services is the most important．In his eagerness to make money from trees, he has cut them down in large numbers, only to find that without them he has lost the best friends he had. And besides, he is usually too careless to plant and look after new trees. So the forests slowly disappear.This does not only mean that man will have fewer trees. The results are even more serious: for where there are trees, their roots break up soil allowing the rain to sink in and also bind(固定) the soil, thus preventing it from being washed away easily；but where there are no trees, the rain falls on hard ground and flows away, causing floods and carrying away the rich top-soil. When the top-soil is gone, nothing remains but worthless desert.Two thousand years ago，a rich and powerful country cut down its trees to build warships, with which to gain itself an empire．It set up the empire, but, without its trees, its soil became poor and grew weak. When the empire fell to pieces, the home country found itself faced by floods and starvation(饥荒)．According to the passage, which is the most important service of trees to man? 大学英语（三） 简述焦虑症的治疗。精神病学 教师通常不做验证电容是电容器自身属性的实验原因是电容器的带电量在传统实验中无法测量错误正确中学物理教学论 10、会计核算有哪些专门方法？成本会计
6[名词解释题]
工程造价
河南理工大学