An idiom/phrase is given in bold. Following this idiom/phrase are given three sentences, which use the given idiom/phrase. The idiom/phrase may or may not be used correctly in one or more sentences. Identify the sentence(s) that use(s) the idioms/phrases incorrectly either in grammar or context and mark the answer accordingly. By the skin of your teeth
I. The student graduated by the skin of his teeth after years of hard work and careful planning.
II. The firefighters rescued the family by the skin of their teeth, moments before the building collapsed.
III. The restaurant built its reputation by the skin of its teeth through years of excellent service and innovation. Which sentence(s) use(s) the idiom incorrectly?