Explain how the regions of china are isolated by geographic features, making governance and the spread of ideas and goods difficult, and served to isolate the country from the rest of the world.

There are many geographical barriers that separate China from the rest of the world, including various seas, mountains, and deserts.  There is the Gobi Desert (north), the Taklimakan Desert (west), the Himalaya Mountains (south), and the Pacific Ocean (east).  China is also isolated by the three seas: the Yellow Sea, East China Sea, and the South China Sea.  Also in the south, there is the Tibet, which is the highest plateau in the world.  There is also the Great Wall of China, which has succeeded many times in keeping out invaders (built by Shi Huangdi).  

The answer is c) people evacuated but almost all returned

Asmall closed hole formed in an outwash plain or moraine. forms when a  glacier retreats then remains stationary.