“教室外狂风暴雨，雷声大作”，这里的“雷声大作”指的是声音特征中的

下列历史人物通过改变或兵变登上皇位的是（    ）

①李世民   ②赵匡胤   ③赵构   ④朱棣

设函数$f\left(x\right)=\left\{\begin{array}{c}{x}^2+bx+c\left(x\le 0\right)\\ 2\left(x>0\right)\end{array}\right.$，若$f\left(-4\right)=f\left(0\right),f\left(-2\right)=-2$，则关于x的方程 $f\left(x\right)=x$的解的个数为（  ）

— ______ do you have the drawing lessons? The pictures you draw are so beautiful.                              
— Once a week. I began having drawing lessons at the age of five.