f（x）=ax+2a+1，在[-1，1]上f（x）的值可正可负，则实数a的范围是_爱下问搜题

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问题填空题

f（x）=ax+2a+1，在[-1，1]上f（x）的值可正可负，则实数a的范围是______．

答案

由于f（x）=ax+2a+1，在[-1，1]上f（x）的值可正可负，故f（x）=ax+2a+1在区间[-1，1]端点的函数值异号，

即 f（-1）f（1）＜0，即（a+1）（3a+1）＜0，解得-1＜a＜-

1

3

，

故实数a的范围是（-1，-

1

3

），

故答案为（-1，-

1

3

）．

单项选择题

病人恐惧不安，首先应采取的正确护理措施是

A．说服指导，减少恐惧

B．嘱家属陪伴

C．给予镇静剂

D．通知医生前来处理

E．在床旁陪伴，随时安慰照顾

完形填空

阅读下面短文，掌握其大意，然后从1 -15各题所给的A、B、C和D项中，选出最佳选项，并在答题卡上将该项涂黑。
" You probably don't remember me," she said. Then she pulled out a piece of paper from her ___1___ and gave it to me. It was my handwriting.
As the assistant of the Honors Programs at the university, one of my __2___ was to review student transcripts(成绩单) to make sure they could ___3___ in Honors. It was common for students to have a(n) ___4___ start and they could no longer continue in Honors after their first term. However, sometimes their ___5___ term report cards would still be sent to us even though the students were no longer in the program.
The note she handed me ___6___, " Congratulations on your excellent second term. You may have been ___7___ with your grades, but you should feel ___8___ of how you've made some progress. Best of luck in keeping up the good work, and you'll be able to succeed."
The student went on and said, " You can't know what this ___9___ to me. I've carried it in my purse for three years and pulled it out anytime I didn't want to do my ___10___. For three years I've been ___11___ to enter your office and giving you this note and this ___12____. " she handed me her latest transcript with good marks.
We were both ___13____. She cried and I ___14____ to. Writing the note seemed like nothing to me, but it meant so ___15___ to her. I really had no idea that my actions had such meaning.

B．disappointed

D．responsibility