搜题请搜索小程序“爱下问搜题”
问题 选择题
设方程有一个正根x1，一个负根x2，则以|x1|、|x2|为根的一元二次方程为（　　）
A．x2-3x-m-2=0B．x2+3x-m-2=0
C．x2-
1-4m
x-2=0		D．x2-
1-4m
x+2=0
答案

A∵|x1|+|x2|=3＞0，但|x1|•|x2|=-m-2不能确定它的正负，∴不能选A．

B∵|x1|+|x2|=-3＜0，∴不能选B．

C∵|x1|+|x2|=

1-4m
＞0，但|x1|•|x2|=-2＜0，∴不能选C．

D∵|x1|+|x2|=

1-4m
＞0，|x1|•|x2|=2＞0，∴选D．

故选D．

听力题

第一节 单词拼写（共10小题；每小题1分，满分10分）

小题1:The girl _________(挑战) me to play a chess game and I accepted.

小题2:We should take some steps to stop the environment being _______    (污染)

小题3:They can grow well because they can ________（吸收）the energy from the heat.

小题4:It was such a difficult problem that there was a _________（困惑的）look on each student’s face.

小题5:Can you tell me how many students our class __________（组成）of ?

小题6:The beautiful scenery __________（吸引）many tourists every year.

小题7:The cartoon series Pleasant Goat and Big Big Wolf《喜洋洋与灰太狼》made a good _________（印象）upon all the boys and girls.

小题8:Though __________（提醒）several times, the man still forgot to attend the meeting.

小题9:She was __________（乐观的）about the future of the company but the others were pessimistic.

小题10:To my anger, he is _________（不断地）changing his mind.
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单项选择题

（）是目前世界上最大的连续动态更新的中国期刊全文数据库。

A.中国知网

B.超星读秀

C.维普期刊资源

D.维普考试资源系统
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