Asking someone to repeat and clarify

Today: asking someone to repeat and clarify. Do Cong Uan, from Vietnam, works at a metalworking company. He came to Japan 8 years ago with his wife. At his job, he helps to shape metal parts and he also mentors junior coworkers. Though he has no trouble with everyday Japanese, he says he struggles when he encounters unfamiliar words. In a roleplay challenge, he must politely ask a superior to repeat and clarify what they said.