题目

阅读短文，根据短文内容和首字母提示写出文中所缺单词。请将单词填写在答题卡上的相应位置。Have you ever heard of the train No. 6063? It links (连接) thirty-eight s【1】 along the way from Baoji of Shanxi to Guangyuan of Sichuan. It passes by twenty-four schools, so there are always many students taking the train. The students live in mountainous areas. And they need to take the train b【2】 schools and homes every week. It always takes a long time for them to go to school and go home on the train. In order to help them, the head of the train Xiang F二次函数f（x）=3x2-4x+c（x∈R）的图象与两坐标轴有三个交点，经过这三个交点的圆记为⊙C．（1）求实数c的取值范围；（2）求⊙C的方程；（3）问⊙C是否经过某定点（其坐标与c的取值无关）？请证明你的结论．