一.填空题
1.An Android project must be bulit before it is run，compiling the java source code(.java flises)into Java bytetcode(.class files)and the into .dex files
2.In Android an activity stores the code for a screen of an app， a layout stores the XML that defines the users interface of an app
3.In an activity，to save values，you can override the onPause method，to restore values you have saved，you can override the onResume method.
4.A simple way to trace the execution of an app is to insert logcat logging statesments at key points in the code，another way to trace code execution is to user toasts，which are messs that are briefly displayed on the user interface.
5.The View class is the superclass for all widgets.A table layout displays widgets in rows and columns.A spinner，also known as a drop-down list，allows the user to select an item from a list .
6.For a seekbar，the OnStartTrackingTouch method is executed when the user begins to change the value of the seekbar.The OnProgresssChanged method is executed when the user changes the value of the seekbar.The OnStopTrackingTouch is executed when the user finishes changing the value of the seekbar.
7.A style is a collection of properties that specify formatting for widget.A theme is a collection of styles that apply to an entire activity or app.
8.An intent provides a description of an operation to be performed.They are commonly used with the startActivity method to start activities.
9.You can use a fragment to define part of the user interface for an activity.
10.By default，an Android app uses a single thread，called the UI thread.The AsyncTask class provides an easy way toperform a background task without having to manually manipulate threads.
11.A service performs tasks in the background，does not provide a user interface ，and continues to run even if the user switches to another app is running.A notification provides a way for a service to display a message even when another app is running.
12.Every broadcast has an action string that uniquely identifies the action.A broadcast receiver is an application component that listens for a broadcast and executes code when it receives that broadcast.
13.You can use the SimpleAdopter class to display data in a ListView widget.
14.Four techniques to implement a listener are use the current class as the listener，used a named as the listener，use an anonymous class as the listener， and use an anonymous inner class as the listener.
15.Android system architecture，known as the Android stack，consists of four layers：Linux ，native libraries，the application framework，and Android apps.
二.选择题
三.综合大题
四.代码大题
