No one knows exactly when humans began eating honey.
问题描述：
No one knows exactly when humans began eating honey.
一道 高一完形填空题 关于蜂蜜的历史以及养蜂对美国农民的影响的.觉得原文句子有毛病（水平低.
答
没有问题啊
没有人知道人类什么时候开始食用蜜糖……
No one 是主语
knows exactly 是谓语
when humans began eating honey.是宾语从句