QUESTION 18 When an argument is passed-by-value, changes in the called function when an argument is passed call-by-reference, changes in the called function value. affect the original variable s value; affect the original variables Do, do. Do not, do not. Do not, do. Do, do not QUESTION 19 When are destructors called? When a program ends When a function ends When a delete operator is used All the mentioned QUESTION 20 Where do bugs occur in a program? There may be errors in the specification itself Poor communication or a misunderstanding of users During the design and implementation phases. All the Above