定义运算：$\left|\begin{array}{cc}{a}_1& a_2\\ b_1& b_2\end{array}\right|=a_1{b}_2-a_2{b}_1$，将函数$f\left(x\right)=\left|\begin{array}{cc}\sqrt{3}& \sin x\\ 1& \cos x\end{array}\right|$的图象向左平移t(t>0)个单位，所得图象对应的函数为偶函数，则t的最小值为（   ）

材料二：带着中期选举的挫败，美国总统奥巴马于11月10日上午抵达北京，出席中国主办的亚太经合组织（APEC）领导人非正式会议。本次会议的主题是“共建面向未来的亚太伙伴关系”。如今中国对外贸易总额的大多数、吸引外资的大部分均来自亚太经合组织成员，中国的发展很大程度上受益于区域经济。而中国的发展，也为亚太经合组织注入了独有的活力和动力。长期以来，中国在亚太经合组织内发挥着极具建设性的作用。中国通过参加亚太经合组织的一系列活动，推动国际秩序朝着更加公正合理的方向发展。

阅读材料，回答问题：

She is a pretty girl ______ long hair.

    In Canada you can find dogs, cats, horses etc, in almost every family. These are their pets. People love these pets and pets are their good friends. Before they keep them at their houses, they take them to animal hospitals to give them needles(针) so that they won't carry disease(疾病). They have special animal food shops, though they can get animal food in almost every shop. Some people spend about two hundred Canadian dollars a month on animal food.

    When you visit people's homes, they would be very glad to show you their pets. You will also find almost every family has a bird feeder (喂食器) in their garden. All kinds of birds are welcomed to come and have a good meal. They are free to come and go and nobody can kill any animal in Canada. They have a law to stop people from killing wild(野生的) animals. If you killed an animal, you would be punished(处罚). If an animal happened to get run over(被碾)by a car, people would be very sad about it.

    People in Canada have many reasons to like animals. One of them is: When children grow up, they leave their parents and start their own work and life. Then their parents will feel lonely, but pets can help them. They can be good friends and never leave them alone.