题目

 y与x+1成反比例，当x=2时，y=1，则当y=－1时，x=_________. 答案：因为y与x+1成反比例所以，把x=2,y=1代入解得k=3，然后把y=-1代入解得x=-4。Lessons can be learned to face the future ________ history cannot be changed.A.thoughB.asC.sinceD.unless