Mr. Trump has focused on narrowing the trade gap between what the United States imports from China and what it exports, but the administration is also pressuring Beijing to scale back subsidies of state-owned enterprises, drastically open its markets to foreign investment and end its longstanding practice of forcing American companies to hand over trade secrets.

请问，句中has focused 作谓语，on narrowing the trade gap between what the United States imports from China and what it exports是介词短语作宾语，between what the United States imports from China and what it exports作the trade gap的宾语，between…and…一般在句中作什么成分？