the exchange of service meaning in Chinese

交换发球权

The visible trade is the import and export of goods , and the invisible trade is the exchange of services between countries
有形贸易指货物的进出口贸易，而无形贸易涉及的是国家间的劳务交换。
In addition to visiable trade , which involves the import and export of goods and merchandise , there is also invisible trade , which involves the exchange of services between nations
除了有形贸易，即进口商品，还有无形贸易，所谓无形贸易就是国家之间交换劳务。