1. 证明（决定、行为或想法）正当；表明…必要
    To justify a decision, action, or idea means to show or prove that it is reasonable or necessary.

    e.g. No argument can justify a war...
           任何理由都不能为战争开脱。
    e.g. Ministers agreed that this decision was fully justified by economic conditions.
           部长们一致同意，这个决定完全符合经济情况。

2. 调整（打印文本）；使齐行；使每行排齐
    To justify printed text means to adjust the spaces between the words so that each line of type is exactly the same length.

    e.g. Click on this icon to align or justify text.
           点击这个图标使文本排齐。