How are programmatic cusomizations done in Salesforce?

Which access modifier should u specify for a class containing the webService keword?
Public
Private
Protected
Global

How are Apex triggers stored?

If the error message contains HTML markup, the escaped markup displays as text and isn’t
rendered in the user interface. (Select all that apply)

Apex code can be initiated in what ways? (Select all that apply)

Apex is available in which Salesforce Editions? (Select all that apply)

The system method, ___________, lets you write test methods that change user contexts to either
an existing user or a new user.

The system method, System.runAs(), lets you write test methods that change user contexts to
either an existing user or a new user.

The System.runAs() functionality can be used to test and verify proper data sharing and data
access. However, System.runAs() does NOT validate CRUD or Field Level Security permissions.

A developer can use optional catch statements for any exception type in a try-catch block.

However, the general exception type, ‘Exception’, must only be used by the last catch() block.
EXAMPLE:
try{
// Some risky code.
}
catch(SomeExceptionType e){
// Handle one exception type.
}
catch(SomeOtherExceptionType e){
// Handle another exception type.
}
catch(Exception e){
// This must be the last catch block.
}
~|~
(Select all that apply)