- I am thinking of going back to school to get another degree.

- Sounds great! _____

圆心角为${135}^{°}$，面积为Ｂ的扇形围成一个圆锥，若圆锥的表面积为Ａ，则Ａ:Ｂ等于(   )

     Bruno was a boy of eight. His father worked in a cinema and his mother worked in a shop. He lived not far from his school. He always walked there and walked home. On his way to school, he had to pass a playground. It was very wet after it rained. One day,when he got home,his clothes were all wet. His mother became angry and said,” don't play in the water on your way home from school!”
    On the next day Bruno came back wet and dirty（脏的）clothes. His mother became even angrier.” I'll tell your father you come back wet again.” said his mother,” He'll punish you,you know.”
    The third day the little boy was dry when he came home.“you're a good boy today,” his mother said happily,”you didn't play in the water.”
   “No,” the boy said unhappily.” There were too many older boys in the water when I got there this afternoon. There wasn't any room（空地方） for me at all.”

如图所示，在与直流电源相接的平行板电容器内部，有一个带电体 P 正好处于静止状态．下列推断正确的是 （   ）