One way of keeping communications secret is to make words invisible.

• a. unable to be seen 

• b. unable to be heard

• c. made useful

• d. known only by a few

Keeping communications secret can be done by writing with a pen dipped in any number of elements.

• a. dropped into a liquid 

• b. sprayed with a liquid

• c. quickly put in and out of a liquid

• d. held down into a liquid

Codes may be made by substituting letters, numbers, or symbols.

• a. breaking 

• b. replacing

• c. developing

• d. creating

The British developed a machine that successfully decoded German messages.

• a. broke into smaller parts    

• b. sent back

• c. discovered the meaning of

• d. made use of

Writing words that disappear is not a reliable way to send a secret message.

• a. continual   

• b. regular

• c. dependable         

• d. hard

The Marines in the Pacific used Navajo "code talkers" to transmit messages.

• a. create

• b. send

• c. hide      

• d. discover

The U.S. military needed an undecipherable code.

• a. easily understood 

• b. impossible to read

• c. difficult to create                   

• d. unable to be sent

The Japanese never cracked the code.

• a. discovered the meaning of

• b. received all the pieces of

• c. made a new language from                  

• d. destroyed the meaning of

Imagine having the police intercept your plans to rob a bank.

• a. throw away

• b. break apart

• c. make a copy of          

• d. stop

Webspeak allows quick communication via cell phones and other electronic devices.

• a. projects     

• b. plans

• c. tools         

• d. ideas