Answer : Option D) Complete.
Explanation : In a complete digestive system, digestion takes place outside of the cells in a series of tubes. Food enters through one opening and food remnants exit out of a different opening. It has examples of humans, dogs, horses, spiders and earthworms. This system is complete because it does not occurs inside a cell nor it occurs in sponge kind-off organs and it is also not incomplete digestion as the waste products are removed from the other opening. 
Therefore, the correct answer is option D) complete.
 
        
             
        
        
        
The acceleration is the change of speed/velocity over time. Thus to calculate this you do (V1-V2)/T or (11.2-9.6)/4 or 0.4 m/s^2
        
                    
             
        
        
        
Answer: the refraction of light by the atmosphere
Explanation: Refraction is the phenomenon in which there is a change in direction of light passing from one medium to another or from a gradual change in the medium. 
Here in case of sunset, the sun rays passes through the varying density of atmosphere because of varying concentrations of dust particles. 
Reflection is the phenomenon in which the light bounces back after falling on a surface.
Absorption is the phenomenon in which matter captures the electromagnetic radiations and thus the energy of photons is converted to internal energy of the system.
 
        
             
        
        
        
Halogens therefore react most vigorously with Group 1 and Group 2 metals of all main group elements.
        
             
        
        
        
In a parallel circuit, the total resistance calculated from the individual resistances is computed from the formula: 1/Rt = 1/R1 + 1/R2. substituting R1 and R2, then 
1/Rt = 1/7 + 1/49 
1/Rt = 1/6.125 = 1/ 49/8
Rt = 49/8 <span>Ω
The total resistance hence is </span>49/8 Ω