题目

Rupert Isaacson was born in Africa and grew up in London and in the English countryside, where he discovered his love of horses. Because he grew up hearing so many fascinating memories about Africa from his parents, he went there and lived with the people called The Bushmen of the Kalahari Desert. By the year 2000, Rupert was already working as a reporter, writing articles and guidebooks about Africa and India. He met his wife Kristin in India. Today, they live with their son, Rowan, in the US. But Rupert faced the greatest challenge of his life when, at the age of two, Rowan was diagn如图，在平面直角坐标系xOy中，我把由两条射线AE，BF和以AB为直径的半圆所组成的图形叫作图形C（注：不含AB线段）．已知A（-1，0），B（1，0），AE∥BF，且半圆与y轴的交点D在射线AE的反向延长线上．（1）求两条射线AE，BF所在直线的距离；（2）当一次函数y=x+b的图象与图形C恰好只有一个公共点时，写出b的取值范围；当一次函数y=x+b的图象与图形C恰好只有两个公共点时，写出b的取值范围；（3）已知?AMPQ（四个顶点A，M，P，Q按顺时针方向排列）的各顶点都在图形C上，且不都在两条射线上，求点M的横坐标x的取值范围．