Many people go to school for an education. They learn languages, history, geography, physics, chemistry and mathematics. Others go to school to learn a skill so that they can make a living. School education is very important and useful. Yet no one can learn everything from school. A teacher，no matter how much he knows, cannot teach his students everything they want to know. The teacher's job is to show his students how to learn. He teaches them how to read and how to think. So much more is to be learned outside school by the students themselves.

    It is always more important to study by oneself than to memorize some facts or a formula(公式). It is actually quite easy to learn a certain fact in history or a formula in maths. But it is very difficult to use a formula in working out a maths problem. Great scientists, such as Einstein, Newton and Galileo didn't get everything from school. But they were all so successful. They invented so many things for mankind. The reason for their success is that they worked hard all their lives, wasting not a single moment. They would ask many questions as they read and they did thousands of experiments.

    Above all, they knew how to use their brains.

过双曲线$\frac{x^2}{a^2}-\frac{y^2}{b^2}=1\left(a>0,b>0\right)$的右焦点F作圆x²+y²=a²的切线FM（切点为M），交y轴于点P. 若M为线段FP的中点，则双曲线的离心率是(   )

如图是将正方体切去一个角后形成的几何体，则该几何体的左视图为（　　）

若2a^3xb^y+5与5a^2﹣4yb^2x是同类项，则x=____；y=____．