已知函数$f\left(x\right)$是定义在$\left(-\infty ,+\infty \right)$上的奇函数，若对于任意的实数$x\ge 0$，都有$f\left(x+2\right)=f\left(x\right)$，且当$x\in 0,2)$时，$f\left(x\right)={\log }_2\left(x+1\right)$，则$f\left(-2011\right)+f\left(2012\right)$的值为(   )

已知图为一几何体从不同方向看的图形：

（1）写出这个几何体的名称；

（2）任意画出这个几何体的一种表面展开图；

（3）若长方形的高为10厘米，三角形的边长为4厘米，求这个几何体的侧面积．

地球仪中“地轴”与球面交点称为两极，其中北极指向（　　）

   To be a good teacher, you need some of the gifts of a good actor; you must be able to hold the attention and interest of your audience; you must be a clear speaker, with a good, strong, pleasant voice which is fully under your control; and you must be able to act what you are teaching, in order to make its meaning clear.
   Watch a good teacher, and you will see that he doesn't sit still before his class; he stands the whole time he is teaching; he walks about, using his arms, hands and fingers to help him in his explanations, and his face to express feelings.There are very important differences between the teacher’s work and the actor's.
   The actor has to speak words which he has learnt by heart; he has to repeat exactly the same words each time he plays a certain part, even his movements and the ways in which he uses his voice are usually fixed beforehand(预先).What he has to do is to make all these carefully learnt words and actions seem natural on the stage. A good teacher works in quite a different way. His audience take an active part in his play: they ask and answer questions, they obey orders, and if they don’t understand anything, they say so. The teacher can't learn his part by heart, but must invent it as he goes along.
   I have known many teachers who are fine actors in class but are unable to take part in a stage-play because they can't keep strictly to what another has written.