1.

a）Define the concept of activity in Android application environment.

b）To navigate transitions between stages of the activity lifecycle in Android development, the Activity class provides a core set of SEVEN (7) callbacks. Briefly explain the callbacks.

2.

Event Listener is an interface in the View class that contains a single call-back method. These methods will be called by the Android framework when the View which is registered with the listener is triggered by user interaction with the item in UI. Describe FIVE (5) call-back methods included in the event listener interface.