已知函数f(x) =2x+1,x∈R.规定:给定一个实数x0,赋值x1= f(x0),若x1≤255,则继续赋值x2=" f(x1)" …,以此类推,若xn-1≤255,则xn= f(xn-1),否则停止赋值,如果得到xn后停止,则称赋值了n次(n∈N *).已知赋值k次后该过程停止,则x0的取值范围是 ()
A:(2k-9 ,2 k-8
B:(2 k-8 -1, 2k-9-1
C:(28-k +1, 29-k+1
D:(27-k -1, 28-k-1
函数y=x2-2x+3的图象的顶点坐标是( )
下列不属于国家为刺激经济增长而采取的积极的财政政策的是( )
长征是中国革命史上不朽的丰碑。下列长征途中发生的历史事件排列正确的是( )
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--A latest English newspaper, please!--Only one copy left. Would you like to have __________, sir?
40+2= 70+3= 10+8= 80+0= 40+5=
3+90= 10+6= 30+2= 50+9= 9+80=
1+10= 8+80= 20+1= 20+3=
0+10= 18–8= 86–6= 68–8= 65–5= 55–50= 93–90= 35–5= 45–40= 75–70= 38–30= 27–20=
57–7= 37–7= 100–30= 66–6=
43–3= 94–90= 34–30= 89–9= 51–1=