问题 填空题

已知{an}是等差数列,a2+a4+a6+a8=16,则S9=(    )。

答案

36

单项选择题
材料分析题

读下表,分析回答:

我国人均资源与世界比较

中国世界中国在世界的位次
人均耕地0.1 公顷0.36公顷11000立方米
人均林地0.12公顷0.9公顷80位
人均草地0.23公顷0.76公顷121位
人均河流径流量2600立方米11000立方米88位

(1)我国自然资源方面的基本特点是什么?                                                                                                                                   (2)怎样对待我国人均资源不足的问题?                                                                                                                                                                                                                                                                                                                                (3)我们在报刊上经常读到有关我国自然资源存在危机的文章,这与我们“资源大国”似乎有矛盾,你    对此有何认识?                                                                                                                                   

                                                                                                                                                               

                                                                                                                                                               

                                                                                                                                                               

(4)造成我国人均耕地不断减少的主要原因有哪些?

                                                                                                                                                               

                                                                                                                                                               

(5)你能说出下边漫画的含义吗?