题目

Mr. Green drove slowly on the way home until he reached the high way, _____ the speed limit was to miles per hour.    A. because      B. which       C. where       D. that 答案：C关于x的一元二次方程x2+（2m+1）x+m2﹣1=0有两个不相等的实数根．（1）求m的取值范围；（2）写出一个满足条件的m的值，并求此时方程的根．