The period during which the presence of  stromatolites decline is the Proterzoic period. Stromatolites are widely distributed sedimentary structures consisting of laminated carbonate or silicate rocks, produced over geologic time by the trapping, binding, or the precipitating of sediment by groups of microorganisms, primarily cyanobacteria. 
        
                    
             
        
        
        
<span>The discovery of thornless plants was made around the turn of the 20th century. To name one such thornless plant, particularly, the Blackberry plant, the deviation from the thorned blackberry canes were discovered in the United States. Since then, several different thornless blackberry varieties have been cultivated for fruit gardens.</span>
        
             
        
        
        
B it will be exactly 100 grams
        
                    
             
        
        
        
I believe its A because all the other one dont make scene really.
        
                    
             
        
        
        
The calcium present in the milk acts as a fertilizer, for the growth of pumpkin size.
Explanation:
Scientific answer: Milk contains nutrients, minerals mainly calcium which are good for the growth of the plant as a fertilizer.
Milk gets readily absorbed by the roots due to the solubility of nutrients in milk.
The root hairs of the plant transport the calcium to the other parts like stem.
This will only help when all other factors of plant growth are present as sunlight, water other than fertilizer.
 Non-scientific question:
 The Hypothesis here is those pumpkin plant fed with milk are bigger on size.
Also injecting stems with milk would cause no good.
Pumpkin plants fed with milk and some plants fed with water are compared, we get the result that giant pumpkins are one that are fed with milk. This is  statistical analysis.