Answer: By the time they came, we had finished our dinner.
Came is past tense, so I would assume it would be had finished
 
        
                    
             
        
        
        
It's B, that they establish an eeri, supernatural mood. Hope this helped
        
                    
             
        
        
        
Answer can be on below areas
1. Microprocessor Manufacturing - Manufacturing has to be automated mainly for two things. 
- Reduce error contribution with human intervention as we cannot design a process where the person will not fail. No such process exits.
- Precision and Repeatability of the product is a requirement.
2. Cleanup Effort in a toxic environment - This has to be automated with machinery as it is very risky to have human intervention and exposure to the chemicals.
        
                    
             
        
        
        
<span>A potential topic for the theme America I believe in You could be centered specifically on the division of the country with the recent election of Trump. With virtually half the nation supporting him and the other half despising him, you could talk about how you believe in America to at least learn how to compromise. You could use compromises from the country in the past, or call to the reader's emotions by reminiscing on "the good times" when we didn't seem as divided.</span>