（Ⅰ）证明当n≥2时，数列{na_n}是等比数列，并求数列{a_n}的通项a_n；

（Ⅱ）求数列{n²a_n}的前n项和T_n；

（Ⅲ）对任意n∈N^*，使得 $\frac{n}{3^{n-1}}{a}_{n+1}$ ≤（n+6）λ 恒成立，求实数λ的最小值．

用日心说否定了影响人类达千年之久的托勒密地心说，有力地推动了人类文明的科学家是（ ）

增加：在缺词处加一个漏字符号（∧），并在此符号下面写出该加的词。

删除：把多余的词用斜线（＼）划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意：1.每处错误及其修改均仅限一词；2.只允许修改10处，多者（从第11处起）不计分。

    Last Saturday I went to the Great Wall with some of my friends.In our way up,we saw many volunteers working in the sun.They helped the elders with their bags,took photo for some tourists and answered people's questions.Because they were very tired,they didn't stop to have a rest.Just at the moment,we saw a little boy standing alone,cried.We went over and asked what is the matter.From his answer we knew he couldn't find her mother.We told him not to worry and then we tried to get in the touch with his mother with the phone number he had given us. Twenty minutes late,his mother turned up,and thanked us again and again.That day we enjoyed the beauty of the Great Wall,and felt the warm of the society.If everyone can reach out helping to others,the world will be more harmonious.