Answer:
 False
Explanation:
An abstract class is a class declared abstract — it may or may not include abstract techniques. It is not possible to instantiate abstract classes, but they can be sub-classed.
<u></u>
<u>Abstract method declaration</u>
               
          abstract void moveTo(double X, double Y);
Usually the subclass offers solutions for all of the abstract techniques in its parent class when an abstract class is sub-classed. If not, however, the subclass must be declared abstract as well.
<u>Example</u>
public abstract class GraphicObject {
   // declaring fields
   // declaring non-abstract methods
   abstract void draw();
}
 
        
             
        
        
        
Answer:
 A switch connects multiple devices to a network. ... devices are usually integrated into a multipurpose network device 
 
        
             
        
        
        
Answer:
The number of invoices for each vendor that have a larger balance due than the average balance due for all invoices.
Explanation:
This part of the code below
 WHERE InvoiceTotal - PaymentTotal - CreditTotal >
(SELECT AVG (InvoiceTotal - PaymentTotal- CreditTotal)
FROM Invoices)
gives the condition to pick the invoices with balance that are greater than the average balance for all invoice.
This part of the code below
GROUP BY VendorName
ORDER BY BalanceDue DESC; 
 then enables the program to group the result of the above condition by VendorName and sort the resulting rows in the order of BalanceDue. You will therefore, obtain for each row in the NumberOfInvoices column, the number of invoices for each vendor that have a larger balance due than the average balance due for all invoices.
 
        
             
        
        
        
Answer:command economy is a key feature of any communist society. Cuba, North Korea, and the former Soviet Union are examples of countries that have command economies, while China maintained a command economy for decades before transitioning to a mixed economy that features both communistic and capitalistic elements