PL SQL -IF THEN ELSIF and nested IF

Review Questions: 1. Explain the syntax of a nested IF statement. 2. In what situations would want to use a nested IF statement? 3. Explain the syntax of an IF THEN ELSIF ladder. 4. How do you compensate for not having curly braces like C language in PL/SQL? 5. How many END IF statements are required in a PL/SQL block? 6. Is END IF always followed by a semi-colon? 7. Write a PL/SQL code to implement an IF THEN ELSIF ladder.