一开始用hello我觉得不够体面和尊敬
你看着办吧!
早安午安晚安
(Good morning/Good Afternoon/Good Evening), teachers. My name is (XX), I am 18 years old and I came from the province of Hebei. I graduated from the second secondary school of Hebei HengShui. At usual times, I enjoy reading all sorts of books. I see myself as a boy with a little bit of shyness. Although my english is not great, I am working hard on it. I am a very studious person, and I feel very lucky to be in here. I hope all of you can like me. Thank you!
最好加个谢谢