为什么可以退税？这个问题涉及到税收政策、国际贸易规则和政府财政等多个方面。以下是对这个问题的解析以及英文翻译对照：

首先，退税是为了促进国际贸易和投资而设立的税收优惠政策。在国际货物贸易中，由于不同国家和地区的税收政策存在差异，因此对商品进口和出口征税的税率也不同。为了促进国际贸易的发展，一些国家采取了退税政策，以减轻出口企业的税收负担，增加出口商品的竞争力。英文翻译为：The reason why tax refunds are possible is to promote international trade and investment by implementing preferential tax policies. In international trade, there are differences in tax policies between different countries and regions, resulting in different import and export tax rates. To promote international trade, some countries have implemented tax refund policies to reduce the tax burden of export enterprises and enhance the competitiveness of exported goods.

其次，退税是为了平衡不同国家和地区的税收负担。在国际贸易中，不同国家和地区的税收政策存在差异，因此同一商品在不同国家和地区的价格也会有所不同。为了平衡不同国家和地区的税收负担，一些国家采取了退税政策，以减轻出口企业的税收负担，提高其产品的国际竞争力。英文翻译为：The second reason why tax refunds are possible is to balance the tax burden among different countries and regions. In international trade, there are differences in tax policies between different countries and regions, resulting in differences in the prices of the same goods in different regions. To balance the tax burden, some countries have implemented tax refund policies to reduce the tax burden of export enterprises and enhance the competitiveness of their products.

此外，退税是为了调整经济结构、促进产业升级和推动经济发展。通过退税政策，政府可以鼓励企业增加投资、扩大生产和提高产品质量，从而促进产业升级和经济发展。英文翻译为：In addition, tax refunds are possible to adjust the economic structure, promote industrial upgrading, and promote economic development. Through tax refund policies, the government can encourage enterprises to increase investment, expand production, and improve product quality, thereby promoting industrial upgrading and economic development.