已知数列{an}满足a1=2,an+1=2an-n+1(n∈N+).(1)证明数

题型:解答题

问题:

已知数列{an}满足a1=2,an+1=2an-n+1(n∈N+).
(1)证明数列{an-n}是等比数列,并求出数列{an}的通项公式;
(2)数列{bn}满足:bn=
n
2an-2n
(n∈N+),求数列{bn}的前n项和Sn
(3)比较Sn
3n
2n+1
的大小.
考点:等比数列的定义及性质等比数列的通项公式等比数列的前n项和数列求和的其他方法(倒序相加,错位相减,裂项相加等)
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“I can't believe what I'm hearing!” I thought to myself. Jeff was the last candidate (候选人) for president of Students’ Union. My best friend Tony came to me and said, “I'm   1 , Mike. I really thought you should be   2 .”

Later that day, I happened to pass Jeff in the dining room. I offered him a polite “  3 ” and walked to my usual table. To my surprise, Jeff put his plate beside mine.
“I'm, er-I'm just wondering  4 you would…consider coming to work on my team,” he said  5 . “You are really smart, and you would be a great manager.”
“I don't think so,” I replied, feeling  6 .
“Well, if you change your mind, we are meeting tomorrow,” he said before moving to  7 table.
All that night, I thought about the offer from Jeff. Maybe being a part of the election process (选举过程)would give me a chance to make important changes at our school. I  8 to join them.
My first goal was to 9 an attractive advertisement. Within a few days, we designed a
 10 with Jeff's pictures showing him in a number of activities. No one could walk through any hallway without passing Jeff's smiling face.
My next step was to  11  which new activities students would like to have at our school. Many of them wanted a chess club and a volleyball team. With the information I had collected, Jeff met with the headmaster. The headmaster  12 to add these activities to our school program.
With my help, Jeff and our ideas were well received at school.
An eighth grader said, “It'll be like attending a new school with Jeff as president.”
Hearing these words made my heart filled with  13 . I had wanted to become president of Student Council to make a difference. I achieved that and more by working as a member of Jeff's team. He became the most popular candidate and I was a large part of his 14 . The fact that it has made a(n)  15 in other people's lives is the real prize. What a great feeling!
小题1:
A.luckyB.happyC.sorryD.angry
小题2:
A.heardB.chosenC.invitedD.followed
小题3:
A.Good luckB.congratulationsC.see youD.help yourself
小题4:
A.howB.ifC.whenD.that
小题5:
A.proudlyB.quicklyC.nervouslyD.shyly
小题6:
A.unhappyB.uncertainC.unnecessaryD.unfair
小题7:
A.otherB.the otherC.anotherD.others
小题8:
A.triedB.refusedC.failedD.decided
小题9:
A.printB.inventC.createD.copy
小题10:
A.posterB.projectC.programmeD.perfomance
小题11:
A.make sureB.look upC.work onD.find out
小题12:
A.agreedB.offeredC.expectedD.managed
小题13:
A.prideB.courageC.kindnessD.hope
小题14:
A.dreamB.futureC.lifeD.success
小题15:
A.differenceB.progressC.mistakeD.effort
题型:解答题

治疗肺心病心力衰竭的首要措施是()

A.卧床休息、低盐饮食

B.使用小剂量强心剂

C.使用小剂量作用缓和的利尿剂

D.应用血管扩张剂减轻心脏负荷

E.积极控制感染和改善呼吸功能

题型:解答题

可能的诊断是

A.高龄初产

B.骨盆入口狭窄

C.骨盆入口和出口狭窄

D.出口狭窄

E.中骨盆和出口狭窄

题型:解答题

本身无活性,需经肝脏代谢转化为活性产物面发挥COX-2抑制作用的药物是()

A、A

B、B

C、C

D、D

E、E

题型:解答题

女性,32岁,阵发性上腹痛2年,夜间加重,疼痛有季节性,冬季明显,有反酸,为进一步确诊,首选的检查方法是

A.X线钡餐检查

B.胃镜

C.胃液细胞学检查

D.胃液分析

E.B超

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