I want to display an image in standard page ?how is it possible?

In a Master Detail relationship ?how many no of hierarchies can be created?
 

Can anyone help me out on thisquestions .I shall appreciate for your help
 
 
3)In a log if all the accounts are deleted from a system.
The client wants to know which user has deleted the accounts ,name ,modified and time frame??
The client is a non techinal person doesnot have any knowledge of the system??
 
4)what are the different sandboxes?
5)what are the ids which gets generated in the sandboxes??
6)what is the major difference b/w the sandboxes??
 
7)I have written a test code in the sandbox and gives me 100% code coverage??
but once i send it to production it gives me 0% code coverage??what will be issue??
 
Thanks in Advance

I have couple of pages in an application.Says as page1,page2,page3,page4,page5.All the five pages are having same content as footer and header??when i add some sentences on page 1 ,it should appear in all the pages .How can u achieve this??

I have two objects one is a standard object i.e Account and the other one is a custom object and their have a look up relations .I have  created 3 text fields as A,B,C in  custom object.Now when I concatenate b/w A and B , the result should get displayed in C.when u type the value manually in field C ,it should throw the error.So which type of trigger is used and how wil u write the code?