"<span>Covered with an enormous sheet of ice" would most likely match Europe, although it should be noted that this was a while ago and changes with time. </span>
        
             
        
        
        
Hello,
An increase in pollution [could] lead to a decrease in <span>genetic variation in a population of tuna.
Faith xoxo</span>
        
             
        
        
        
Answer:
The correct answer will be- Crop rotation
Explanation:
When the growth of a type of crop which uses soil nutrients in abundance and then growing another crop in the same filed led to the decrease in the production of the next crop.
Thus farmers adapted to avoid such farming practices and developed a new practice which allowed the land to become fertile again so that the growth of next crop will not be affected.
The practice involved the planting of a crop on a piece of land then leaving the soil ploughed and unsown for a longer period of time and growing corp on another piece of land allowing the time to restore the nutrient content. This practice is known as "crop rotation".
Thus, crop rotation is the correct answer.
 
        
             
        
        
        
False negative is a condition when you got a negative result for a specimen which was positive. To prevent false negative occur, first you need to use golden standard test or a test with high specificity. You can do multiple tests to ensure the specimen is negative and using a positive control to make sure the reagent is still working fine.