阅读下列短文,从每小题所给的A、B、C、D四个选项中选出一个最佳选项。

Dear Bill

    Thank you for your letter（信件). You tell me something about your family. Now I'll talk about my family.

    I have a happy family. We love each other. My grandparents are doctors. They work in Canada now. My parents are both teachers. They teach English at Luoyang International School. My sister and I are in Luoyang with them.

    I'm 13 years old. I'm a student in Grade Seven. I like my teacher and my friends in China . They often help me. I want to be a Chinese doctor when I grow up . Now I can speak Chinese. My sister, Jane, is only three years old. She is very cute . She has brown hair and blue eyes. We all love her.China is very beautiful. Welcome to China.

Yours

Frank

亚马孙雨林破坏严重，关于破坏原因的叙述，错误的是(     )

在△ABC中，角A，B，C所对的边分别为a，b，c，已知$\frac{2a+b}{c}$=$\frac{\cos \left(A+C\right)}{\cos C}$

（1）求角C的大小，

（2）若c=2，求使△ABC面积最大时a，b的值．