1. The oldest person at the party was an octogenarian who still had a lot of energy and enthusiasm. 这次聚会上最年长的人是一位八旬老人，他仍然充满了能量和热情。
2. My grandmother is an octogenarian, but she is still sharp-minded and active. 我的祖母是一位八旬老人，但她仍然头脑敏锐、活跃。