阅读短文，选择正确的答案。

    This is Lucy and that is Lily. Lucy is 12 years old. Lily is 12 years old, too. Lucy looks like Lily and Lily looks like Lucy, too.

    They look the same. They are twins. But they have different hobbies. Lucy likes listening to music and drawing pictures. Lily likes dancing and playing basketball. They are American. They are new students in Jim's class .They are in Grade Six. Jim often looks after them. They are new friends. They go to a shop. They would like something to eat and drink. Lucy would like some bread.   Lily would like a bottle of orange. Jim would like some apples.  

设集合$U=\left\{\left(x,y\right)|x\in R,y\in R\right\}$，$A=\left\{\left(x,y\right)|2x-y+m>0\right\}$，$B=\left\{\left(x,y\right)|x+y-N\le 0\right\}$=，则点$P\left(2,3\right)$$\in A\cap \left(C_{u}B\right)$的充要条件是（   ）