Question: តើអ្នកណាបានស្នើសុំថាភ្នែកត្រូវមានប្រដាប់ទទួលពន្លឺ ៣ ពណ៌
Answer: ថូម៉ាសយ៉ង់; แฮร์มัน ฟ็อน เฮ็ล์มฮ็อลทซ์