地球公转时围绕的旋转中心是（　　）

促使拓跋部由游牧转向农耕定居生活的因素有(     )

①解散部落组织，实行编户　　 ②计口授田，劝课农桑

③宗主督护制　　　　　　　　 ④兴办太学

根据图1、图2回答问题：

Do you believe in love at the first sight? Many people answer "No, we don’t", but I say I do.why? I’ll tell you my story.
From childhood, I like people with blue eyes. I had a few dolls and I painted their eyes blue. I was really very happy with my blue-eyed dolls. Time rushes by quickly, and soon I was not a child any more. I had finished my studies as I was 20.
I liked to drive my father’s old car. Once I went to a nearby town .I was busy that day.I left my car near the office where I had to go. In a few minutes, I came back and a young policeman was waiting for me near my car. I was not happy to see him. He tried to explain that I had parked my car in the wrong place, but I couldn’t pay my attention to his words. I had to stare at his beautiful blue eyes. He repeated his words but I did not bear him well. He became serious and began to speak in a loud voice.I paid him the fine(罚款)and I said to him" Your eyes are so nice."
He smiled and said goodbye to me.
In the evening this blue-eyed policeman called me up. The following day we went to the cinema. After that, my story has a happy ending. We married and we now live happily together.