5.The desperate plight of the South has eclipsed the fact that reconstruction had to be undertaken also in the North，though less spectacularly．

(同位语从句fact that…)

南方极为严重的困境使北方同样需要开始重建(尽管不像南方那么引人注目)这一事实显得不太重要。

分句1: The desperate plight of the South has eclipsed the fact

分句2: reconstruction had to be undertaken also in the North

分句3: though less spectacularly （省略）

1和2嵌套

1和3并列