Test analysis: Since18th century, China has been in a super position in Sino-British trade. In order to reverse the trade deficit, Britain smuggled opium into China, plundered a lot of silver from China, and destroyed the physical and mental health of China people. So d belongs to the direct purpose, and ABC belongs to the influence.
Comments: Surplus is trade surplus, which refers to the surplus formed by a country's foreign trade in a certain period of time, and its export value is greater than its import value, also known as trade surplus. The purpose of British opium smuggling to China is to reverse the trade deficit with China and obtain high profits.