①该班的同学都非常珍惜自己班级的荣誉  ②该班是一个团结友爱的班集体

③该班的每个同学都对自己的班级有主人翁责任感 ④该班的同学都愿为集体贡献力量

设O－ABC是四面体，G₁是△ABC的重心，G是OG₁上的一点，且OG＝3GG₁，若$\overrightarrow{OG}$＝x$\overrightarrow{OA}$＋y$\overrightarrow{OB}$＋z$\overrightarrow{OC}$，则(x，y，z)为(　　)

以下说法中正确的是（  ）

先通读下面的短文，掌握其大意，然后从A、B、C、D四个选项中选择可以填入空白处的最佳答案．

Dear Tony,

    I'm glad to1you．Now let me tell you something about my2life．I was born in3village．It was not big but4was beautiful and clean．There5a big garden．Near the garden was my first school，6I walked to school.My first teacher was7 and nice,but she was also8us.My best friends are Wang Mai and Li Dong.Wang Mai was good at all9and he was the top pupil(尖子学生)．Li Dong was good at football and he was a member of our school football team．

    I am looking forward to going back to my school and 10 my teachers and friends．

Yours，

Du Ming

下列四个国家中，属于下图所示I类国家的是