已知等差数列{an}中,a1+a2+…+a9=81且a6+a7+…+a14=17

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问题:

已知等差数列{an}中,a1+a2+…+a9=81且a6+a7+…+a14=171,则a5=______,公差d=______.

考点:等差数列的定义及性质
题型:填空题

()车门处脚蹬须为焊装,其他脚蹬须为铆装。

题型:填空题

记忆力减弱()

A.34℃

B.33~32℃

C.32~31℃

D.26~25℃

E.20~18℃

题型:填空题

阅读理解。

     We could all see the Murray Uiver slowly moving back, but now all the water was gone. I couldn't believe

that the Murray had dried up, not one drop of water left.

     One morning I went down to the river to try and catch some fish when I saw my boat high and dry (搁浅)

on the bank. I rushed down the river and saw all mud-no water. The fish were just lying there, dying. I looked

up to see if my friend was there. There was the nest but no eagle (鹰). I called out to her with my special

whistle which I made out of steel.

     Suddenly a big shadow came over to me and the eagle landed in her nest and gave her young the food she

was out getting while I whistled. But then I suddenly noticed she was getting thinner and had a bit of sheep's

wool in the side of her talon (利爪). It was deadly quiet by the river bank, except for some sound from my dog.

And also I couldn't see one native animal or bird.

     When I walked inside the kitchen, Mum and Dad had sad looks on their faces. "It's time for us to move,

Son, because the river can no longer provide for (养活) us," said Dad. I ran out of the kitchen door with tears

in my eyes, and down to the river bank, to my favorite spot. I said goodbye to my eagle, crying.

     When it was time to go, I saw my eagle fly up into the air with her chicks in her talons, going away to try

and find another home, just like us.

1. The passage is mainly about _____. [ ]

A. the author's travel away from his hometown

B. the author's feeling about being away from his friend

C. the author's idea about being away from home

D. the author's plan to leave for a new place

2. The underlined word "chicks" in the last paragraph refers to "_____". [ ]

A. the eagle's children

B. the eagle's food

C. the eagle's nest beside the river

D. the dog

3. According to the passage, the eagle looked thinner most probably because _____. [ ]

A. the eagle had to feed its children

B. the eagle was seriously sick

C. the eagle lost many of his friends

D. there was not enough food for her

4. According to the passage, it can be inferred that _____. [ ]

A. the eagle lived on the ground beside the author's house

B. it was winter when the writer went away

C. the writer's parents didn't like to leave, either

D. some native animals and birds still lived in the place

题型:填空题

界址未发生变化宗地的地籍变更一般( )到实地进行变更地籍测量。

A.不必

B.需要

C.不需要

D.必须

题型:填空题

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