单选题 Though many thought him a tedious old man, he had a ______ spirit that delighted his friends.
【正确答案】 D
【答案解析】(youthful富于青春活力的)。句意为:尽管许多人认为他是一位讨厌的老人,但他充满青春活力的精神让他的朋友们感到高兴。A.juvenile幼稚的,B.meek温顺的, C.leaden无表情的。