利用所学的生物学知识回答下列问题：．

如图所示，两个可视为质点的、相同的木块A和B放在转盘上，两者用长为L的细绳连接，木块与转盘的最大静摩擦均为各自重力的k倍，A放在距离转轴L处，整个装置能绕通过转盘中心的转轴O₁O₂转动，开始时，绳恰好伸直但无弹力，现让该装置从静止开始转动，使角速度缓慢增大．

已知平面$\alpha$∥平面$\beta$，点P∈平面$\alpha$,平面$\alpha$、$\beta$间的距离为8，则在$\beta$内到点P的距离为10的点的轨迹是（    ）

阅读短文，下列问题

 B

The wolves(狼) are very hungry. They go out to look for food. There are many sheep near the hill. There are also a few sheepdogs with them. The wolves think of an idea. They speak to the sheepdogs, “You are like us and we are brothers. But we have a very different life. We do what we like, and you must work for men. They make you look after their sheep. They eat meat and give you the bones(骨头). If you listen to us and give us the sheep, we can eat them together. All of us will be happy, right?” The dogs are happy and do like this. The wolves ask the dogs to go to their house. The sheepdogs go to the wolves’ home. But the wolves eat them and then eat the sheep.