These Hawaiian Islands Attractions Offer A Surprising Look At Lava Tubes
"those / these" are determiners and are used before nouns to refer to a particular group of things / people, e.g. these people / those rules / those buildings. Update: 题主问的是What are those? 然后他.
Lava Tubes - Hawaiʻi Volcanoes National Park (U.S. National Park Service)
