Question 1

WebClient's ________ method terminates its executing asynchronous task.

Accepted Answer

A) TerminateAsync 
B) CancelAsync 
C) DeleteAsync 
D) RemoveAsync

Question 2

If a long-running calculation were to be performed synchronously in a GUI app,________.

Accepted Answer

A) the GUI app would split off the long-running calculation into a separate thread. 
B) the GUI would freeze until the calculation completed and the user would not be able to interact with the app 
C) the app would terminate 
D) the app would deadlock

Question 3

Executing asynchronous methods in separate threads on a dual-core computer typically ________ executing the same tasks sequentially.

Accepted Answer

A) takes more time than 
B) takes about the same amount of time as 
C) takes less time than 
D) takes an unpredictable amount of time compared to

Question 4

________ programming is a technique for writing apps containing tasks that can execute asynchronously,which can improve app performance and GUI responsiveness in apps with long-running or compute-intensive tasks.

Accepted Answer

A) synchronous 
B) object-oriented 
C) task-oriented 
D) Asynchronous

Question 5

Task property ________ returns the value returned by a Task.

Accepted Answer

A) Result 
B) Value 
C) TaskReturn 
D) TaskValue

Question 6

A MethodInvoker (namespace System.Windows.Forms)is a ________.

Accepted Answer

A) a single-argument constructor 
B) Delegate that invokes a method with no arguments and a void return type 
C) an interface that must be implemented 
D) an indirect proxy caller

Question 7

Because ________,asynchronous Tasks are frequently used in GUI apps that invoke web services (or perform network communication in general)to ensure that the apps remain responsive.

Accepted Answer

A) there can be unpredictably long delays while awaiting a web-service response 
B) synchronous tasks don't work well in GUI apps 
C) web services are not designed to work with synchronous Tasks 
D) memory is limited in GUI-based web services

Question 8

An app that performs synchronous tasks on a single-core computer often takes longer to execute than on a multi-core computer,because ________.

Accepted Answer

A) it's too costly to convert them to asynchronous tasks 
B) the processor is shared between the app and all the others that happen to be executing on the computer at the same time 
C) multi-core computers have no overhead 
D) single-core compters generally have slower processors

Question 9

When you await a Task,if that Task has already completed,execution simply continues.Otherwise,control returns to ________ until the result of the Task is available.Once the Task completes,the async method continues execution.

Accepted Answer

A) the async method 
B) the await clause 
C) the async method's caller 
D) the await method's caller

Question 10

Class WebClient's ________ method starts a new Task<string> in a separate thread and uses the URL specified as the method's string argument to request information from a web server.

Accepted Answer

A) RequestWebStringAsync 
B) QueryWebStringAsync 
C) StartTaskStringAsync 
D) DownloadStringTaskAsync

Question 11

A ListBox's ________ property indicates the source of the data that populates the ListBox's Items collection.

Accepted Answer

A) DataSource 
B) DataOrigin 
C) DataCreator 
D) DataIssuer

Question 12

Today's ________ computers,smartphones and tablets enable computers to perform tasks truly concurrently.

Accepted Answer

A) large memory 
B) multiscreen 
C) soft keyboard 
D) multicore

Question 13

Handling short computations in the GUI thread ________.

Accepted Answer

A) does not cause the GUI to become unresponsive 
B) makes the GUI appear choppy. 
C) indefinitely potpnes the GUI. 
D) deadlocks the GUI.

Question 14

An async method can perform other statements between those that launch an asynchronous Task and await the Task's results.In such as case,the method continues executing those statements after launching the asynchronous Task until it reaches ________.

Accepted Answer

A) the await expression 
B) the return statement 
C) the Task return 
D) the async return

Question 15

Tasks that proceed independently of one another are said to execute ________ and are referred to as ________ tasks.

Accepted Answer

A) synchronously,synchronous 
B) independently,independent 
C) asynchronously,asynchronous 
D) intensively,intensive

Exam 23: Asynchronous Programming With Async and Await