When you are doing an assignment for school, take for example English, and you want to use another website's words, you would put them in quotation marks, which would be quoting them instead of plagiarism. You would also put their info at the bottom of the page and that would be your source of where you got your quote from.
Explanation: All answers could work except answer 5. You shouldn’t end a friendship just because of a small fight. Talk it over. (I mean unless you really don’t like this person)
The sentence in which the underlined infinitive phrase functions as a subject is the last one - to quickly move large groups of people is the purpose of public transportation. <em>To quickly move </em>is the infinitive phrase, and it is a subject.
