材料1：我国第十二个五年规划纲要提出，加强重点生态功能区保护和管理，增强涵养水源、保持水土、防风固沙能力，保护生物多样性，构建以青藏高原生态屏障、黄土高原—川滇生态屏障、东北森林带、北方防沙带和南方丘陵山地带(两屏三带)以及大江大河重要水系为骨架，以其他国家重点生态功能区为重要支撑，以点状分布的国家禁止开发区域为重要组成的生态安全战略格局。

材料2：下图为我国“两屏三带”生态安全战略格局图。

材料3：下图为“某地社会、生产、生态系统联系图”。

（Ⅰ） 求c，a_n；

（Ⅱ） 若 $b_n=\frac{a_n}{2^n}$ ，求数列{b_n}前n项和T_n．

   阅读下面短文，根据短文内容判断句子的正误。正确的涂“A”，错误的涂“B”。
   When I was a boy, I didn’t have any hair on my head. So I was very shy. I liked to watch my friends play in the park. Sometimes I would join them, but most of the time I just watched them play.
   Every day, we would see an old man walking in the park. He had big ears and no hair. We thought he was dumb (哑的). Every time when my friends saw him, they would say loudly, "Hey, Mr. Dumb, what’s the time?” But they got no answer.
   One early evening, I was standing outside my house, and I saw the old man coming. I was not with any of my friends and there were no other kids around to say the usual words of "greeting( 问候)”.
   But how could I let the old man walk by without saying anything? So for the first time, I asked, “Hey, Mr. Dumb, what’s the time?"
The old man looked at me. Then he looked at his watch and answered, "It’s six thirty. " I ran into my house and never said that "greeting" to the old man after that day.