此地有400多英里的航道有待勘察。
There are more than 400 miles of waterways to explore in the area.
在刘和他的团队对那里的岩石进行勘察的过程中，他们发现了70多个类似足迹的斑点——在沉淀物中的一些浅痕，其周边有轻微的突起。
As Mr Liu and his team explored the rocks they came across more than 70 markings that looked like tracks - slight impressions in the sediment with tiny ridges sticking up along the sides.
在刘和他的团队对那里的岩石进行勘察的过程中，他们发现了70多个类似足迹的斑点——在沉淀物中的一些浅痕，其周边有轻微的突起。
As Mr Liu and his team explored the rocks they came across more than 70 markings that looked like tracks-slight impressions in the sediment with tiny ridges sticking up along the sides.
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