Answer:
The turning points are those instants, moments or situations that happen in an absolutely unexpected way, as a result of which your life changes ... and nothing is the same as before. 
 
        
                    
             
        
        
        
Answer:
Rube Goldberg Machine is "a comically involved, complicated invention, laboriously contrived to preform a simple operation." 2. What are the 6 Simple Machines? A. The 6 Simple Machines are: wedge, screw, lever, wheel and axel, inclined plane and pulley.
 
        
             
        
        
        
It starts or speeds up.
Some substances need certain amount of energy in order to react with each other.
        
                    
             
        
        
        
Answer: 
The force of friction acting on block B is approximately 26.7N.  Note: this result does not match any value from your multiple choice list. Please see comment at the end of this answer.   
Explanation: 
The acting force F=75N pushes block A into acceleration to the left. Through a kinetic friction force, block B also accelerates to the left, however, the maximum of the friction force (which is unknown) makes block B accelerate by 0.5 m/s^2 slower than the block A, hence appearing it to accelerate with 0.5 m/s^2 to the right relative to the block A.
To solve this problem, start with setting up the net force equations for both block A and B:

where forces acting to the left are positive and those acting to the right are negative. The friction force F_fr in the first equation  is due to A acting on B and in the second equation due to B acting on A. They are opposite in direction but have the same magnitude (Newton's third law). We also know that B accelerates 0.5 slower than A:

Now we can solve the system of 3 equations for a_A, a_B and finally for F_fr:

The force of friction acting on block B is approximately 26.7N. 
This answer has been verified by multiple people and is correct for the provided values in your question. I recommend double-checking the text of your question for any typos and letting us know in the comments section.
 
        
                    
             
        
        
        
Answer:
C. community
Explanation:
Community consists of a local residence, like a town.