1. Western commodities dominate: during this period, China imported mainly from Europe and America, including textiles, machinery, chemicals, food and precious metals.

2. Increased imports of industrial products: With the development of industrialization, the proportion of industrial products in China's imported goods is getting higher and higher, such as machinery and equipment, raw materials, etc.

3. Trade imbalance: During this period, China's trade surplus was serious, and the trade volume of China's imported goods was much lower than that of its exported goods.

"Characteristics" refers to the unique or remarkable characteristics of a thing or event, or it is obviously different from other things or events.