_____ calling uses an app such as Skype, Google, Hangout, or What's Up to call another person

Forgetting to register an event-handler object for a particular GUI component’s event type causes .

a. events of that type to be ignored. b. all of the GUI component's events to be ignored. c. a compilation error. d. None of the above.

A recurrence ____________________ schedules an appointment at regular intervals for a designated period of time.

Fill in the blank(s) with the appropriate word(s).