Which of the following protocols does DNS utilize on port 53?

In Word, press and hold this key before you click a hyperlink

a. Esc b. Ctrl c. Shift

Which of the following statements about abstract superclasses is true?

a. abstract superclasses may contain data. b. abstract superclasses may not contain implementations of methods. c. abstract superclasses must declare all methods as abstract. d. abstract superclasses must declare all data members not given values as abstract.