North korea has developed a very weak economy by

After World War 2 the Northern Korean government forced the markets to be domestically based (employing self-reliance) which means that they tended to buy most products locally and produced most products locally. This was done in order to decrease their dependence on China and the Soviet Union. This also caused their government to invest in outside markets like steel. Once their government began to heavily "upgrade" their military, this made them focus on their heavy machinery and metals industries. However, after the oil crisis caused by an oil embargo ( an embargo is a ban on trade for a specific product), the demand (and thus their international prices) for their domestically produced products like those in the heavy industry (mining and steel) as well as their minerals dramatically decreased and North Korea fell into massive debt. While the government and the Juche regime repeatedly continued to construct skyscrapers and other unnecessary structures rather than focus on their debt, the economy continued to decline. Once the communist states began to fall apart, North Korea could no longer depend on them for financial help, and they continued to develop a weak economy.

Explanation:

a bad leader      

the vibration from the sound waves messed with the glass and it shattered.

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