1. **Stop sb because of a problem:** - Sentence: The teacher had to stop the student because of a problem with their assignment.2. **To live in a city:** - Sentence: Many people choose to live in a city for the convenience and opportunities it offers.3. **Doing sth to find an answer:** - Sentence: She spent hours doing research to find an answer to the challenging question.4. **Speaking to the texts in Ex. 5 again:** - Sentence: When speaking to the texts in Exercise 5 again, I noticed several key points that were worth discussing.Note: The fourth phrase seems incomplete. It might need additional clarification or correction for a more accurate sentence.