It can change one thing into onether witch sometimes can be bad
        
             
        
        
        
Due to huge effect use of Drought the population of animal get extinct.
Explanation:
Droughts can have a severe impact on the extinction of animal populations, specifically in Arid and Semi environments. Different type of climate changes can accelerate the dying of particular species or animal population.  
 For extinction of population and also species Droughts play vital role. Droughts are one of such severe climatic change that leads to the extinction of species. Some life traits of specific Species make it vulnerable to drought.  
 
        
             
        
        
        
Answer:
In this case, the scientist want to test the presence of the limonite in the yellow rocks, So, proposed hypothesis should include the color of rock they want to observe and the posssible outcome, which need to be tested. So, a proposed hypothesis can be: The rocks, which have yellow color are made up of mineral lime.
 
        
             
        
        
        
B. the nervous system connects bones