14.下列说法正确的是( )
| A. | “任意画一个三角形,其内角和是360°”是随机事件 | |
| B. | “明天的降水概率为80%”,意味着明天降雨的可能性较大 | |
| C. | “某彩票中奖概率是1%”,表示买100张这种彩票一定会中奖 | |
| D. | 晓芳抛一枚硬币10次,有7次正面朝上,当她抛第11次时,正面向上的概率为$\frac{7}{10}$ |
13.下列不等式一定成立的是( )
| A. | 3-x<4-x | B. | -b>-2b | C. | 4a>3a | D. | $\frac{3}{c}>\frac{2}{c}$ |
11.把a$\sqrt{-\frac{1}{a}}$根号外面的因式移到根号内得( )
| A. | -$\sqrt{-a}$ | B. | $\sqrt{-a}$ | C. | -$\sqrt{a}$ | D. | -1 |
10.下列各数:$\sqrt{5}$,3+$\sqrt{29}$,0,$\root{3}{4}$,$\sqrt{25}$,2π,$\frac{22}{7}$,-1.732,其中无理数有( )
0 286681 286689 286695 286699 286705 286707 286711 286717 286719 286725 286731 286735 286737 286741 286747 286749 286755 286759 286761 286765 286767 286771 286773 286775 286776 286777 286779 286780 286781 286783 286785 286789 286791 286795 286797 286801 286807 286809 286815 286819 286821 286825 286831 286837 286839 286845 286849 286851 286857 286861 286867 286875 366461
| A. | 2个 | B. | 3个 | C. | 4个 | D. | 5个 |