1. Improve digestion: Vitamin C and cellulose in oranges can help digest food and maintain intestinal health, while tannic acid in black tea can promote intestinal peristalsis and digestion.

2. Antioxidants: Oranges and black tea are rich in antioxidants, which can scavenge free radicals in the body, slow down cell aging and prevent diseases.

3. Improve immunity: Vitamin C in oranges and black tea can improve human immunity and prevent diseases such as colds and flu.

4. Help to lose weight: Both black tea and oranges have the function of losing weight. For people who want to lose weight, making black tea with oranges is a healthy drink choice.