What was the primary economic purpose of constructing the Grand Canal during the Sui dynasty?

To create a new trade route for selling silk to Europe

To provide a reliable water source for the capital city

To link the food-producing south with the political north

To build a series of defensive moats to protect border towns

Which statement best describes the situation in China during the 300 years before the Sui dynasty was established?

It was unified under the peaceful and popular Han emperors

It was fragmented into separate kingdoms that were constantly at war

It was controlled by nomadic invaders who conquered the entire country

The population enjoyed great prosperity due to a boom in foreign trade

The Gobi Desert and the Pacific Ocean

The Tibetan Plateau and the capital city

The Great Wall and the Silk Road

The Huang He and Chang Jiang rivers

Constant attacks from pirates along the coast

The division of the country into separate, warring kingdoms

A severe famine that destroyed the agricultural system

The complete collapse of trade on the Silk Road