Answer:
a cell membrane is a double layer of lipids and proteins that surrounds a cell
 
        
             
        
        
        
Answer: single; quantitative
Explanation:
The discounted cash flow analysis is a method that is used to determine the value of a project, security, or assets by using time value of money. 
The discounted cash flow analysis is used in real estate, investment finance, patent valuation etc. A modified DCF analysis is best for evaluating and selecting the optimal strategic alternative when a company has single goal(s) and quantitative measures.
 
        
             
        
        
        
Answer:
The opportunity cost will be Buying a new lawnmower
Explanation:
Opportunity cost refers to the cost of a forgone alternative. In this scenario, since the owner of a landscaping business has decided to spend the extra income on advertising campaign in order to increase sales, the forgone alternative here becomes buying a new lawnmower.
 
        
             
        
        
        
Answer: Malika's job starts in one month, so she will have one month without work. Therefore, the opportunity cost of moving herself is low during this month.
Explanation:
From the question, we are informed that Malika just got hired by Amazon to work in upper management and that she currently lives in South Carolina, and has to move to California for the job.
A good economic reason for her to move her personal belongings on her own rather than hiring someone else is Malika's job starts in one month, so she will have one month without work. Therefore, the opportunity cost of moving herself is low during this month.
Since her job will start in a month, that means that she can use the available time she has to move her personal belongings. Assuming, she has something else to do or she'll be busy and will be hard for her to move it on her own, then it'll be logical to request for someone to help her move it but in this case, she can move it herself as the opportunity cost is low.