请写出一个解为-1，且方程左右两边都含有未知数x的一元一次方程______．
2x=x-1，答案不唯一．
故答案是：2x=x-1．
偏移距
_____ good his English is, he still has a long way to go.[ ]
A. Although
B. Even if
C. Whatever
D. However
