What is the fine-grained topic of the following text: Heilongjiang Tengyuan International Trading Co., Ltd a professional import&export manufacturing company, engaged electronic products, chemical raw material import, and furniture products export over 18 years, including a great variety of dining tables, wood and metal door, window, and office stationery . Only return the topic.
Import and export activities of Heilongjiang Tengyuan International Trading Co., Ltd.