1. Sleep is something that has really been an unexplored topic cross-culturally. 在各种文化中，睡眠是一个未被探索的话题。
2. Archaeologist Bill Kelso and his team discovered the church in a previously unexplored area of the fort in Jamestown. 考古学家比尔·凯尔索和他的团队在詹姆斯敦之前未开发的的堡垒区域发现了这座教堂。
3. There appear to be many unexplored matters about the motivation to reflect—for example, the value of externally motivated reflection as opposed to that of teachers who might reflect by habit. 反思的动机方面似乎有许多问题尚未被探索——例如，与教师可能进行的习惯性反思相对的，受外部激励的反思的价值。
4. But this is unexplored terrain. 但这里是未知地带。
5. There are very few places in the world that remain unexplored. 世界上只有极少数地方尚未勘探过。
