已知圆 $\Omega$ 过点 $A\left(5,1\right)$ ， $B\left(5,3\right)$ ， $C\left(-1,1\right)$ ，则圆 $\Omega$ 的圆心到直线 $l$ ： $x-2y+1=0$ 的距离为____．

已知命题p：∃x₀∈R，x₀²﹣2x₀+3≤0的否定是∀x∈R，x²﹣2x+3＞0，命题q：双曲线 $\frac{x^2}{4}$ ﹣y²=1的离心率为2，则下列命题中为真命题的是（   ）

windy

根据短文内容，选择正确答案。
B
    Nick is my pen pal. He is 12 years old. He is from Canada. He lives in Ottawa. He speaks English and French. His favorite subject is science. He likes Chinese, too. And he says he can speak a little Chinese, but he can't write in Chinese.
    Nick likes sports, too. He likes swimming best. He goes swimming on weekends with his father. He says he can swim very well. He doesn't like physics. He thinks it's too difficult.
    Nick has a big family. There are nine people in his family, his grandpa, grandma, father, mother and his brothers and sisters. He has two brothers and two sisters. They are Bob, Tim, Jane and Susan. They are happy!

下列说法不正确的是（  ）