除全额保证金外，办理国外保函业务的申请人评级应为（）以上。
A.AA
B.A
C.BBB
D.B
参考答案：C
Companies are struggling to find the right _____between supply and demand, but it is no easy work .
A．methods
B．equal
C．balance
D．design
比例尺是一个比，所以它没有单位．______．
