试题题干
Translate the following sentence into Chinese.
This is an unexplored area in vitamin research and the only known advantages of vitamin E are confined to specialized medical cases.
参考答案
试题解析
考点：unexplored area 未探查的领域；be confined to 局限在；specialized case 特定案例。
句子结构：句子为一个并列句。前半句为一个简单句。后半句为被动语态be confined to，译成中文时改为主动语态。