将长方体截去一部分后的几何体如图所示，它的俯视图是   （）

     The children often play soccer in the garden(花园). Sometimes they break (打破).Mrs. Smith’s windows.  
One afternoon , Mrs. Smith is reading a newspaper at home. After a short time, she closes her eyes and goes to sleep. At that time a little boy knocks(敲) at the door. Mrs. Smith opens the door and asks, “Do you break my windows again（又一次）?” “Oh, no”, says the boy. “ Your windows are open this time and our soccer is in your room. Can I get it back, please?” 
根据短文内容，选择正确答案。

“我们不把任何未经验证的意见接受作为真理，而是遵照必要的次序，从一步推演到下一步……不论多么深奥，最终都能发现。”与这句话的理念一致的说法是（  ） 

若数列$\left\{a_n\right\}$前8项的值各异，且a_n+8=a_n对任意的$n\in N$都成立，则下列数列中可取遍$\left\{a_n\right\}$前8项值的数列为（   ）