The response "Some caves, however, turn this on its head and form from the bottom up." is the missing information from the description of cave formation. This statement introduces an alternative process of cave formation that is not covered in the original description, which focuses on caves forming through the dissolution of rock from the top down. The other two options do not provide new or missing information that would enhance the understanding of the cave formation process as described.
Caves are mysterious environments; but for all their strangeness, most caves are formed from three commonplace ingredients: rock, water, and organic matter. Only rock that can dissolve in water will form caves—rocks such as limestone, chalk, dolomite, marble, or even salt. Rainwater, when introduced to this rock, will seep through tiny pores or dribble through larger cracks. As the rain, which is slightly acidic, trickles down, it begins to dissolve the rock. The final catalyst needed to make caves is plant matter. In wet regions, thick mats of organic material accumulate. Rainwater percolates through the soil, becoming caustic carbonic acid. Over many thousands of years, this process produces caves.
Which of the following information is missing from the description of cave formation?
Responses
Some caves, however, turn this on its head and form from the bottom up.
Pick the answer below.
Generally, rainwater has a ph of 5—the same acidity as black coffee.
Pick the answer below.
The decomposition of this matted organic material produces carbon.
1 answer