题目

____, the driver looked at the vast desert without knowing if he could get across safely.  A. Tired and sad      B. Tired and sadly      C.Tiredly and sad    D.Tiredly and sadly 答案：A已知抛物线与x轴交于两点、，与y轴交于点C，AB=6．【小题1】（1）求抛物线和直线BC的解析式．【小题2】（2）在直角坐标系中，画出抛物线和直线BC．【小题3】（3）若⊙P过A、B、C三点，求⊙P的半径．【小题4】（4）抛物线上是否存在点M，过点M作轴于点N，使被直线BC分成面积比为的两部分？若存在，请求出点M的坐标；若不存在，请说明理由