For example, changes in the economy that lead to fewer job opportunities for youth and rising unemployment 1 make gainful employment increasingly difficult to obtain.
[A] in general [B] on average [C] by contrast [D] at length
in general基本上等同于normally,generally speaking,totally,in the main及mainly,在句中多表示“一般而言,总的来说”,作状语; on average为“平均”的意思,基本上会涉及到数量关系及统计;by contrast“相比之下”的使用往往涉及比较;at length是“最后,终于,详细地”的意思,这里并未出现时间或空间顺序的含义,故答案在定在“in general”(整个社会现象)。
参考译文:
For example, changes in the economy that lead to fewer job opportunities for youth and rising unemployment in general make gainful employment increasingly difficult to obtain.