2. The Following is the source code that will need to do the mutation testing, how many mutants can be given to this source code, and list each mutants and explain why you did this kinds of mutants? (10 points)

Public Function isLeap(year) As Boolean Dim year As Integer Dim c1, c2, c3 As Boolean 1. c1 = (year % 4 == 0) 2. c2 = (year % 100 == 0) 3. c3 = (year % 400= = 0) 4. isLeap = False 5. If ( (c1 AND NOT(c2)) OR (c3)) Then 6. IsLeap = True 7. EndIf 8. End Function

3. Why do we do the software testing?The following picture is about the software testing cost at each stages for three different kinds of defects, please explain this graph. (10 points)

4. We have introduced the error, fault, and failure, please explain the relationship among this three terminology, and write a source code to mark where is the error happened, how the fault appear, and what is the failure caused , and also explain it. (10 points)

5. When do we stop to do testing? What is the stop reasons? (10 points)

|9Requirements defect Design defect Code defect Requirements Design Implementation Verification Maintenance