写出一个关于x，y的二元一次方程，使它的自然数解有且只有三个，这个方程可以是______．
方程为x+y=2，
故答案为：x+y=2
— Could you please tell us about some good ways to learn English?
— My suggestion is that reading often and writing regularly _____. [ ]
A. are needed
B. is needed
C. be needed
D. should need
单户损失类本金余额为200万元的贷款原则上应由（）认定审批
A．支行
B．二级分行
C．一级分行
D．一级分行风险部门
