题目

补全对话A: What were you doing yesterday morning?B: What about you?A: No, I wasn't. I went to the park with my family.B: What did you do there?A: I climbed the mountain and my mother took some photos.B:A: He was lying(躺) under the tree and reading a book.B: Was your sister climbing the mountain, too?A: No, she wasn't. B: How exciting! I think I will go there next week.A. She was playing with some children.B. Were they swimming in the river?C. I was helping my father water the flowers.D. What was your father doing while you were climbing the mountain?E. Was your sister drawing in the par已知等比数列{an}的前n项和Sn=2n-a，n∈N*．设公差不为零的等差数列{bn}满足：b1=a1+2，且b2+5，b4+5，b8+5成等比．（Ⅰ） 求a及bn；（Ⅱ） 设数列{an}的前n项和为Tn．求使Tn＞bn的最小正整数n的值．