The problem will appear_a different welfare system will be created.A unless B whether C untill Dif

问题描述:

The problem will appear_a different welfare system will be created.A unless B whether C untill Dif

A unless 是“如果不”表条件,正确;
B whether是“是否”,词义错误;
C untill 是“直到.”,表示时间,错误;
Dif 是“如果”表条件,但词义错误.