读短文，完成下面各题。

    Hello, my name is Li Ming. My birthday is June 9th. My mother's birthday is June 14th. My grandpa's birthday is June 23th.My grandpa is in America, my grandpa lives with my uncle Bill and aunt Mary in America, so I usually make an e-card to him for his birthday.

My grandma's birthday is in July, it is very hot and sunny in July, then when her birthday is coming, we often go swimming for her birthday.  

定义在$R$上的函数$f\left(x\right)$满足$f\left(x+1\right)=-f\left(x\right)$，当$x\in 0,1$时$f\left(x\right)=-\left|x-\frac{1}{2}\right|+\frac{1}{2}$，则$f\left(\frac{5}{2}\right)-f\left(\frac{99}{2}\right)=$ (       )

利用电解法可将含有Fe、Zn、Ag、Pt等杂质的粗铜提纯，下列叙述不正确的是（　　）