完形填空

　　I have a good name, Henry. I am fourteen years old. I1England. I’d like2you my dream in the future. I will be a doctor3ten years. I will work in London4it is a beautiful city. It’s our capital. As a doctor, I will meet all kinds of sick people. But I’m glad5help people. I will live in a big house6my family because I don’t like7alone. I will have a car, a nice car. 8I can’t drive now. Because I’m too young, my mother9allow(允许)me to drive now. I will have a robot. The robot will help me10my housework. I hope my dream will come true one day.

已知$\left|\overrightarrow{a}\right|=1,\left|\overrightarrow{b}\right|=3,<\overrightarrow{a},\overrightarrow{b}>={60}^{°},(\overrightarrow{a}-\overrightarrow{c})(\overrightarrow{b}-\overrightarrow{c})=0,$则$\left|\overrightarrow{c}\right|$的最小值是(     )

如图，设数轴上的点A，B，C表示的数分别为a，b，c，则下列说法中错误的是（　　）