Skate park is a good example that maintains the law of conservation as skater neither creates nor destroys energy.
Explanation:
As per the law of energy conservation, energy cannot be created nor can be destroyed but it’s form can definitely be changed. This theory can be well justified by the example of skate park playground. According to the rules of this law a skater can never go high more than 2 meters on the ramp’s other side because it has that gravitational energy potential.  
With every drop of the skater on the ramp the potential energy of the skater changes into kinetic energy. This two sides of the law justifies the fact that skate playground should be designed in such a way that it supports the law of conservation of energy.
 
        
                    
             
        
        
        
Answer: 
I) Sexual reproduction 
II) Mutation 
Explanation:
Variations refer to the difference observed within organisms of the same species. Variation are introduced into a population by:
- new genetic combinations that occur during sexual reproduction (i.e during meiosis)
- mutations, spontaneous changes that occur in genes and chromosomes.
 
        
             
        
        
        
The correct answer is "letter c. malingering."
Malingering is described as falsifying symptoms of mental or physical well-being of a person to achieve a certain goal, an example is that malingering a certain mental illness or physical illness may be used as a mitigating factor to reduce the sentence of a criminal or to receive special treatment in prison. It may also be used to skip school or work in the military. 
        
             
        
        
        
Reaches the adult stage is the correct answer. When an intervebrate reaches the adult stage it has most likely stopped growing and can finally begin reproduction, passing further down the line his genes and the genes of his ancestors. 
        
                    
             
        
        
        
The answer would be D. Huntington's disease presents symptoms in humans after many have already reproduced; therefore, they are unaware that they passed on Huntington's disease.