为什么货币贬值？这个问题涉及到货币供应、经济政策和国际贸易等多个方面。以下是对这个问题的解析以及英文翻译对照：

首先，货币贬值是为了增加出口、促进经济增长和调整国际收支。当一个国家的货币贬值时，出口商品的价格相对下降，这会使得出口商品更具竞争力，从而促进出口增长。此外，货币贬值还会使得进口商品价格上升，从而刺激国内生产和就业。英文翻译为：Firstly, currency depreciation aims to increase exports, promote economic growth, and adjust the balance of payments. When a country's currency depreciates, the price of exported goods falls relatively, which makes these goods more competitive and promotes exports. In addition, currency depreciation also raises the price of imported goods, thereby stimulating domestic production and employment.

其次，货币贬值还受到货币政策和经济因素的影响。当一个国家的央行想要增加货币供应量来刺激经济增长时，货币贬值是一个可能的后果。此外，经济衰退、通货膨胀和贸易摩擦等经济因素也可能导致货币贬值。英文翻译为：Secondly, currency depreciation is also influenced by monetary policy and economic factors. When a country's central bank wants to increase the money supply to stimulate economic growth, currency depreciation is a possible consequence. In addition, economic factors such as recession, inflation, and trade frictions may also lead to currency depreciation.

此外，货币贬值还受到国际贸易和全球经济一体化的影响。在全球经济一体化的情况下，各国之间的贸易和投资联系日益紧密，货币之间的汇率波动也会相互影响。当其他国家的经济增长乏力或者货币汇率上升时，全球投资者可能会寻求将资金投入这些国家的市场，从而推高美元汇率。英文翻译为：In addition, currency depreciation is influenced by international trade and global economic integration. In the context of global economic integration, trade and investment relationships between countries are becoming increasingly interconnected, and the exchange rate fluctuations between currencies also influence each other. When other countries' economies perform poorly or currency exchange rates rise, global investors may seek to invest their funds in these countries' markets, thereby driving up the exchange rate of the US dollar.