Drug and alcohol abuse among children.

The effects of video-game violence on children.

Diets high in sugar and salt among children.

The effects of explicit lyrics in music on children.

The German annexation of Austria.

The Soviet occupation of Germany.

The landing of Allied soldiers on Normandy Beach.

The Japanese attack on Pearl Harbor.

Mechanical reapers to replace horse-drawn reapers.

Stronger and cheaper material for railroads and bridges.

Transistors of radios.

Electric lightbulbs.

To enforce laws prohibiting discrimination.

To integrate public schools.

To enforce privacy protections.

To integrate the armed forces.

A decline in the number of women working in urban factories.

A shift away from the traditional roles of women.

An increase in the use of credit and installment plans.

A decrease in crime associated with the prohibition of alcohol.

Communist Party.

Civilian Conservation Corps.

Navajo Code Talkers.

Flying Tigers.

A trade imbalance with Asia.

The spread of communism in Asia.

The educational opportunities available in Asia.

An environmental disaster in Asia.