美元的涨跌受到多种因素的影响，主要包括以下几个方面：

1. 经济因素：美国的经济状况是影响美元涨跌的重要因素之一。当美国的经济增长强劲、就业市场繁荣、消费者信心高涨时，美元往往会上涨，因为这些因素可以提高投资者的信心，促使他们购买美元资产。相反，如果美国经济出现衰退、失业率上升、消费者信心下降等情况，美元往往会下跌。英文翻译为：Economic factors are one of the important factors that affect the fluctuations of the US dollar. When the US economy performs strongly, the employment market prospers, and consumer confidence is high, the US dollar tends to rise because these factors can boost investors' confidence and encourage them to purchase US dollar assets. Conversely, if the US economy experiences a recession, the unemployment rate rises, and consumer confidence declines, the US dollar tends to fall.
2. 政策因素：美国联邦储备系统（FED）的政策也会对美元的涨跌产生影响。FED可以通过调整利率和货币供应来影响美元的汇率。如果FED提高利率或增加货币供应，美元往往会下跌，因为这些政策可以鼓励投资者购买其他货币或资产。相反，如果FED降低利率或减少货币供应，美元往往会上涨。英文翻译为：Policy factors also have an impact on the fluctuations of the US dollar. The Federal Reserve System (FED) can adjust interest rates and money supply to affect the exchange rate of the US dollar. If FED raises interest rates or increases money supply, the US dollar tends to fall because these policies can encourage investors to purchase other currencies or assets. Conversely, if FED lowers interest rates or reduces money supply, the US dollar tends to rise.
3. 政治因素：政治因素也会影响美元的涨跌。例如，如果美国出现政治危机、战争、恐怖袭击等事件，投资者可能会担心政治不稳定会对经济产生负面影响，从而降低对美元的信心，促使美元下跌。相反，如果美国的政治局势稳定、社会治安良好，投资者可能会增加对美元的信心，促使美元上涨。英文翻译为：Political factors can also affect the fluctuations of the US dollar. For example, if there are political crises, wars, terrorist attacks, or other events in the United States, investors may worry that political instability will have negative effects on the economy, reducing their confidence in the US dollar and prompting it to fall. Conversely, if the political situation in the United States is stable and social order is maintained, investors may increase their confidence in the US dollar and prompt it to rise.

综上所述，美元的涨跌受到多种因素的影响，包括经济因素、政策因素和政治因素等。这些因素之间相互作用，共同决定着美元的走势。英文翻译为：In summary, the fluctuations of the US dollar are influenced by various factors, including economic factors, policy factors, and political factors. These factors interact with each other and jointly determine the trend of the US dollar.