Bill is an English boy. He is twelve. He lives in China with his family. There are four people in his family. They are his father Jack Cliton, his mother Catherine and his little sister Abby. He has a yellow dog. Its name is Barbi. His father is mending his bike. What is Bill doing? Ah, he is doing Chinese homework. He can't speak Chinese very well. But he loves Chinese very much. Bill's father works in middle school. He is an English teacher. His mother is in a TV factory. Bill and his sister go to the same school.

________ my father _______ my mother is able to drive a car. However, they are going to buy one.

三棱柱的顶点个数是（　　）

已知  $y=(a+1)x^2+ax$是二次函数，那么a的取值范围是　____　．