福州江滨大道缤纷园入口处，安装了两盏“风光互补”景观节能灯，如图所示，它“头顶”小风扇，“肩扛”太阳能电池板。关于节能灯的设计解释合理的是 （   ）

下列说法：
①命题“存在$x\in R,2^x\le 0$” 的否定是“对任意的$x\in R,2^x>0$”；
②关于x的不等式$a<{\sin }^{2}x+\frac{2}{{\sin }^{2}x}$恒成立，则a的取值范围是a<3；
③函数$f\left(x\right)=a{\log }_2\left|x\right|+x+b$为奇函数的充要条件是a+b=0；

其中正确的个数是（   ）

   My name is Tom. My best friends are John and Ann. John lives near my house and we are in the same class. He’s tall and thin, he has blonde hair and blue eyes. He is polite and very clever. He is very good at math and sometimes helps me with my homework sometimes. He usually wears jeans and a blue T--shirt. We three often play basketball in a nearby park.
   My friend Ann studies at another school.She’s short and slim(苗条的) with straight brown hair and brown eyes. She’s a little bit shy. We all have Kong fu lessons every Tuesday and Friday afternoon. We love Kung fu very much. Ann is really good at Kung fu. We call her the “Kong fu girl”. Sometimes she practices Kung fu with us. She loves wearing a T—shirts and a hat. The three of us have great fun together.