因為of是介詞，而動詞不能做介詞的賓語，所以要用動名詞形式，即動詞+ing。
例句：
One of the penalties of fame is loss of privacy.
成名的弊端之一是失掉了隱私。
Ive had enough of the pair of you!
你們倆讓我煩透了！