I believe it is K or rather potassium
        
             
        
        
        
1 ) The first terrarium was developed by botanist Nathaniel Bagshaw Ward in 1842. He was interested in studying insect behaviour. Once he accidentally left one of his bug jars open. A fern spore in the jar sprouted, grew and germinated into a new plant. This is how the first terrarium had been created.
2 ) <span />Because of the different conditions within, terrariums there are two, which can be classified as closed and open. Closed terrariums have a lid to enclose the plants entirely within the glass container. Open terrariums do not require a lid.
Sorry working on this right now as well, and I don't have the others yet :(
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Answer:
A. Class
Explanation:
Kingdom can be answered but the most specific is class
 
        
             
        
        
        
The excessive use of water for irrigation in dry climates, with heavy soils, causes salt accumulation because they are not washed out by rainfall. The practice of waterlogging without adequate drainage has also become a serious cause of soil salinization .