单选题 At 90, many individuals still remain healthy and energetic.
A. intelligent B. rough
C. robust D. revivable

【正确答案】 C
【答案解析】intelligent:智能高的;rough:粗糙的;robust:费体力的,健全的; revivable:可复兴的。题中energetic意为“精力旺盛的”,所以选C。