人物事迹介绍类写作 — 英语词汇题

根据中文提示，补全下列描写时代楷模事迹的句子中所缺的单词（首字母已给出）。1. Yuan Longping was a great s______（科学家）who helped many people. 2. He worked hard all his life and never gave u______. 3. We should learn from these role m______（榜样）of our time. 4. Zhong Nanshan is brave and always h______（帮助）people in need.