阅读下面短文，按照句子结构的语法性和上下文连贯的要求，从1-15各题所给的A、B、C和D项中选出最佳选项。"Our teas can help protect your teeth and your heart, possibly even helping to prevent cancer," said Luo Shengkai, one of four student hosts from Sichuan University High School. They 1 introduced three self-made health teas through a livestream (直播) on Douyin 2 March 27, 2022, and they 3 for several weeks by now. The livestream got over 60 4 likes and many online orders, with all profits (收入) going to local tea farmers.
"It's 5 first time we have sold tea online. We not only need to introduce 6 tea, but we also need to interact with the audience and answer their questions," said Luo. "We've learned a lot from the process, 7 it's tiring."
Luo is one of a group of students 8 take part in a two-year course on tea research. They learn about tea planting and picking, tea making, package design and marketing through research and fieldwork.
However, 9 a new and popular tea isn't easy. Luo and his team members 10 a tea to better protect students' eyesight. They first met with a professional from Chengdu University of Traditional Chinese Medicine and researched the properties (特性) of local tea. Then they learned 11 functions of ingredients such as goji berries (枸杞), mangosteen (山竹果) and cassia seed (决明子) and did experiments to find what would happen if they 12 all together. They ended up with a cassia seed tea and then added 13 ingredients based on people's feedback.
"Through the tea course, students 14 learn how to be creative and improve their hands-on skills. They also learn to respect tea workers and how to contribute to rural vitalization (乡村振兴). That's 15 our educational means." said Mi Yunlin, the principal of the school.
