justify後加doing。
因爲它是（及物動詞，後接名詞、代詞或動名詞）“表明或證明（某人/某事）是正當的、有理的或公正的”：
Such action can be justified on the grounds of greater efficiency.以提高功效爲依據可以證明採取這種措施是正確的。
You shouldn't attempt to justify yourself.你不應想方設法證明自己有理。
You can't justify neglecting your wife and children.你不關心妻子兒女是說不過去的。
