已知（1+ax）6的展开式中，含x3项的系数等于160，则实数a=______．_爱下问搜题

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问题填空题

已知（1+ax）⁶的展开式中，含x³项的系数等于160，则实数a=______．

答案

∵（1+ax）⁶的展开式为 T_r+1=

C

r6

•（ax）^r，令r=3，可得含x³项的系数等于a³•

C

36

=160，

解得 a=2，

故答案为：2．

完形填空

Seven loyal（忠实的）readers came to the Teens Office two weeks ago. They had a wonderful day learning how to make a newspaper. But what       made them excited was that they had their say. “What most __    me was when I was saying something, I found all eyes were on me,” said Tang Shining, one of the students. Her friend, Li Chunbei __, and felt very glad that when she was talking, the editors（编辑） nodded and __    took notes.
Students are happy to see the editors listen to their __    . You may often __    about being neglected（忽视） by teachers and parents. ___ before complaining, please make sure that you have already spoken about your _    _.
Traditionally in China, teachers at school and parents were__      the ones to tell teenagers what they should and shouldn’t do. The young are __     to doing what they are told, rather than thinking by themselves. But then their ideas would be locked in their brain and not be __   .
A girl wrote to Teens about her family story. She ___    to be very sad because her father seldom talked and played with her. After years of consideration, she          _ decided to write her father a letter, telling him about her sadness. To her __   , the father _   , saying that he didn’t realize his mistake. From then on, he really __  .
Sometimes, we need to let our ___ be heard, so others can understand our thoughts and feelings.Don’t be afraid of being __    for what you have done. You know it is your _39_ to speak your mind. Even if your suggestions are denied, at least you have tried your best. You will not be left with any __   .

D．immediately

A．disappointed

D．horrified （恐惧）

C．hatred憎恨

A．sorrow（悲伤）

B．disappointment

D．satisfaction

C．suggestions

单项选择题

川芎的药用部位为( )

A．根

B．根茎

C．根及根茎

D．块根

E．块茎