IAR Prep - "What's So Special About Secret Codes?

Which sentence from the passage “What’s So Special About Secret Codes?” expresses the central idea of the passage?

• “Secret codes are powerful ways of sending messages and keeping information hidden.” (paragraph 1)

• “Codes have brought down monarchs and whole armies and, today, they can make computers work or cause them to crash.” (paragraph 2)

• “Hiding a message is the earliest form of code and it is called steganography.” (paragraph 4)

• “A code is a system of symbols, letters, words, or signals that are used instead of ordinary words and numbers to send secret messages or store information.” (paragraph 7)

Based on the answer in Part A, which sentence from the passage states an idea that should be included in a summary of the passage?

• “Creating, carrying, and cracking codes can be exciting and dangerous, and can even save lives.” (paragraph 1)

• “Using a code makes sure that messages are understood only by the people they are intended for—from soldiers to popes.” (paragraph 2)

• “Many modern cryptographers use computer languages or codes to help them encrypt and decrypt their messages.” (paragraph 3)

• “But hidden writing is risky, because once the messenger or device is searched, the message is revealed easily.” (paragraph 7)

In paragraph 5 of the passage from “What’s So Special About Secret Codes?” the author describes the method used by Chinese people 2,000 years ago to hide codes. Which of these steps should not be followed in order to hide and show a message using this method?

• The sender boils the egg in water.

• The sender writes the message with invisible ink on the shell.

• The recipient translates the message into numeric code.

• The recipient sends the message on the egg.

How does paragraph 5 contribute to the reader’s understanding of secret codes?

• It illustrates a common method of hiding messages still used today.

• 
  It demonstrates that people have been hiding messages for many centuries.

• It shows how people have used wax to hide messages in the past.

• It explains some of the reasons why people need to send messages.

What is the author's primary purpose in writing this passage?

• To persuade the reader to learn how to create secret codes.

• To inform the reader about the history and importance of secret codes.

• To entertain the reader with a fictional story about spies.

• To describe how computers use secret codes in modern times.

How does the author develop the idea that secret codes have played an important role in history?

• By listing different types of codes used in the past and present.

• By describing how secret codes are difficult to understand.

• By explaining why secret codes should only be used by trained professionals.

• By showing how secret codes have only been useful in times of war.