When can a developer use a custom Visualforce page in a Force.com application? (Choose 2)

What is the return data type when ApexPages.currentPage().getParameters() is used to retrieve URL parameters from a visualforce controller?

Which tool allows a developer to send requests to the Salesforce REST APIs and view the responses?

When the number of record in a recordset is unknown, which control statement should a developer use to implement a set of code that executes for every record in the recordset, without performing a .size() or
.length() method call?

A developer wrote a unit test to confirm that a custom exception works properly in a custom controller, but the test failed due to an exception being thrown. What step should the developer take to resolve the issue and properly test the exception?