The answers are:
C
A
Hope it helps :)
        
                    
             
        
        
        
Answer:
Java Class given below
Explanation:
class ReadOnly
{
protected int val;
public ReadOnly(int arg)
{
val = arg;
}
public int getVal()
{
return val;
}
}
class ReadWrite extends ReadOnly
{
private boolean dirty;
public ReadWrite(int arg)
{
super(arg);
dirty = false;
}
public void setVal(int arg)
{
val = arg;
dirty = true;
}
public boolean isDirty()
{
return dirty;
}
}
 
        
             
        
        
        
Answer:
Apple Laser Writer is an example of a DTP <u>Hardware.</u>
Explanation:
DTP means Desktop Publishing. It may include the hardware and software. The DTP hardware includes two major parts a computer and a printer. The DTP software includes the software such as Photoshop, illustrator an other software that needs in desktop publishing.
Apple laser writer is a printer that is used to print the text and diagrams that we make using DTP software tools. 
 
        
             
        
        
        
Open source is created and updated by a worldwide community of programmers and is available for free. Many students are in luck, as they can easily study publicly accessible codes and have a possibility to make better software. It also has lots of advantages, such as getting <span>high-quality results when the source code is passed around, tested and fixed.The most important thing - it<span> is a valuable learning opportunity for programmers and opportunity to improve their skills.</span></span>
        
             
        
        
        
21%4 is 1.
21-4=17
17-4=13
13-4=9
9-4=5
5-4=1