Answer:
It would mimic the behavior of the earth's atmospheric atmosphere where you have a water cycle and sunlight which aids photosynthesis.
Step-by-step explanation:
A terrarium is a glass container that can be covered and opened at will. It can be used to grow a plants using soil.
When it is sealed, water evaporates onto the body of the glass and runs down the sides of the glass only to be evaporated again and the same process happens over and over again.
Because the plants are in a glass container, they can still access sunlight for photosynthesis.
Sometimes the glass is opened up for maintenance. Maintenance here refers to the removal of algae that sometimes forms on the inner walls of the terrarium. Sometimes, there is also need to add water to the ecosystem in the terrarium given that the water inside usually escapes via evaporation over time.
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