已知数列{an}是等差数列,且a1=2,a1+a2+a3=12. (Ⅰ)求数列{ 发布时间:2017-05-04 12:59 │ 来源:www.tikuol.com 题型:解答题 问题: 已知数列{an}是等差数列,且a1=2,a1+a2+a3=12.(Ⅰ)求数列{an}的通项公式;(Ⅱ)令bn=an3n(x∈R).求数列{bn}前n项和的公式.
题型:解答题 完型填空。 When I was about five years old, I used to watch a bird in the skies of southern Alberta from the Blackfoot Blood Reserve in northern Montana where I was born. I loved this bird; I would 1 him for hours. He would 2 effortlessly in that gigantic sky, or he would come down and light on the 3 and float there beautifully. Sometimes when I watched him, he would not make a sound and liked to move 4 into the grasses. We called him meksikatsi, which in the Blackfoot language 5 "pink-colored feet"; meksikatsi and I became very good friends. The bird had a very particular significance to me 6 I desperately wanted to be able to fly too. I felt very much as if I was the kind of person who had been born into a world where 7 was impossible. And most of the things that I 8 about would not be possible for me but would be possible only for other people. When I was ten years old, something unexpected 9 my life suddenly. I found myself become an 10 child in a family I was not born into; I found myself in a 11 position that many native Americans findthemselves in, living in a city that they do not understand at all, not in another culture but 12 two cultures. A teacher of the English language told me that meksikatsi was not called meksikatsi, even though that is what 13 people have called that bird for thousands of years. Meksikatsi, he said, was really "duck". I was very 14 with English. I could not understand it. First of all, the bird did not look like "duck", and when itmade a 15 , it did not sound like "duck", I was even more 16 when I found out that the meaning of theverb "to duck" came from the bird. As I 17 to understand English better, I understand that it made a great deal of 18 , but I never forgot that meksikatsi made a different kind of meaning. I 19 that languages are not just different words for the same things but totally different 20 , totally different ways of experiencing and looking at the world. ( )1.A. keep ( )2.A. jump ( )3 .A. nest ( )4.A. quickly ( )5.A. means ( )6.A. though ( )7.A. communication ( )8.A. dreamed ( )9 .A. improved ( )10.A. educated ( )11.A. weak ( )12.A. between ( )13.A. most ( )14.A. desperate ( )15.A. noise ( )16.A. ashamed ( )17.A. tried ( )18 .A. evidence ( )19.A. identified ( )20.A. concepts B. watch B. dive B. hill B. naturally B. reads B. because B. imaginationB. worried B. enriched B. adopted B. comfortable B. against B. few B. bored B. call B. confused B. came B. distinctionB. confirmed B. regulations C. follow C. circle C. water C. freely C. shows C. while C. belief C. knew C. changed C. outgoing C. terrible C. without C. their C. uncomfortable C. decision C. embarrassed C. determined C. profit C. realized C. messages D. search D. wander D. road D. quietly D. states D. until D. flight D. argued D. ruined D. independent D. central D. beyond D. my D. disappointed D. choice D. frightened D. expected D. sense D. predicted D. evaluations 查看答案
题型:解答题 书面表达(满25分)假设星期天你带外国朋友在我市游览,请根据图中游览顺序写一则日记。日记须包括图中所有内容。可以适当增加细节和感想,使日记连贯完整。日记的开头已经写好,不计入总词数。注意:1.词数100左右2.活动顺序: ①友谊饭店。上午8:10出发。②中山公园(看花展)③市博物馆④金山寺(观江景)⑤海鲜酒楼(the Seafood Restaurant)。下午1:20回原处。 查看答案