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问题 选择题
下列方程中是一元二次方程的是（　　）
①ax2=bx；          ②-
3
2
x2-2x=
1
3
；   ③（x-2）（2x-1）=0； 
④x2-
1
x
-2=0；  ⑤y2-
1-y
=1；  ⑥（x-3）（x+1）=x2-8．
A．①②④⑥B．②C．①②③④⑤⑥D．②③
答案

①当a=0时，ax2=bx不是一元二次方程，故本小题错误；

②-

3
2
x2-2x=
1
3
是一元二次方程，故本小题正确；

③（x-2）（2x-1）=0是一元二次方程，故本小题正确；

④x2-

1
x
-2=0，分母上有未知数，不是整式方程，不是一元二次方程，故本小题错误；

⑤y2-

1-y
=1，被开方数有未知数，不是一元二次方程，故本小题错误；

⑥（x-3）（x+1）=x2-8，整理不含二次项，不是一元二次方程，故本小题错误；

综上所述，②③．

故选D．

单项选择题

“夫君子之行，静以修身，俭以养德，非淡泊无以明志，非宁静无以致远”出自（）。

A、《朱子家训》

B、《诫子书》

C、《颜氏家训》
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单项选择题

Activity Based Costing (ABC) is an (11) technique that allows an organization to determine the actual (12) associated with each product and service produced by the organization without regard to the organizational structure. This chapter explains some of the uses and benefits of Activity Based Costing. We use IDEFO (13) modeling in conjunction with ABC to enable more effective business (14) design decisions.

In order to achieve the major goals of business process improvement, process simplification and improvement, FAA managers need to fully understand the cost, time, and quality of activities performed by employees or machines throughout an entire organization. ABC methods enable (15) to cost out measurements to business simplification and process improvement.

（14）是（）

A.data

B.benefit

C.process

D.image
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