参考词汇：垃圾分类 trash sorting
Having learned that you are interested in the trash-sorting program promoted recently in China, I am here writing to give you a brief introduction.
As far as I know, Shanghai has become the pioneer of our country's waste sorting policy. As of July 1st this year, the residents in Shanghai have not been able to dump their waste bags in whichever bin was closest. On the contrary, domestic waste is required to be classified into four categories: dry refuse, wet trash, recyclable waste and hazardous(dangerous) waste.
Faced with the new rule, many citizens in Shanghai are finding it a little too complicated, with every item of waste now under careful scrutiny(examination) and classification. Still, there are more people who warmly support the policy because it helps people to cultivate greener lifestyle habits and helps China to become a more beautiful country.
As we all know , the time of 5G technology is coming , it is called the fourth industrial revolution , future of computer science lies in the artificial intelligence，it is the research and artificial simulation of human thought and eventually be able to make a human like to think the same machine , for human services and to help people solve problems.
After all, people thought it was unique, there are feelings, there are a variety of character, this will be very difficult to achieve in the machine.In fact, to do the same as the human thinking machine, the only one of the artificial intelligence, is by no means all. Through the study of artificial intelligence, it can resolve all kinds of scientific problems, promote the development of other science will have a great impact on all people's lives .
I believe that the science of artificial intelligence is waiting for humanity to explore it step by step .
参考词汇：流行病epidemic 疫情 epidemic situation 新型冠状病毒 novel coronavirus
Dear Medical workers，
I am Li Hua,a high middle school student in Shanxi. I'm writing to express sincere gratitude to you all for your devotion and sacrifice in this battle against the Novel Coronavirus.
In this epidemic, it is you who, despite the lack of equipment and the potential of infection, desperately rescue those infected but striving for life. It is also you who have shed new light on the virus with expertise to build up our confidence to defeat it. It is you who deserve all the admiration and love!
I can never express our thankfulness too much for your selfless contribution. It's widely believed that our joint efforts China will win the battle and make a quick recovery.
Good luck and stay well!
One possible version：
Nowadays, after-class activities are becoming increasingly popular in senior high school.We also have many kinds of after-class activities in our school, such as the English Corner, Sunshine Radio Station, Happy Reading Club and so on.
I’m interested in the English Corner, because it can not only help me make some new friends but also improve my spoken English.In addition, I’m fond of the Sunshine Radio Station, where I can have an unforgettable experience and make good friends. I hope my dream of being a host may come true one day.These after-class activities make me feel more confident.
If you want to take part in after-class activities，I have some suggestions.First, you had better choose the activity which you like best.Second, try to make the best of your interest.
I’m Li Hua, an exchange student from China during this summer vacation. I’m delighted to learn that volunteer students are wanted for a Chinese painting exhibition to be held in the local art gallery. Now I’m writing to apply for the position.
The reasons for my application are as follows. First of all, having been exposed to foreign teachers since a young age, I can communicate freely with others in English. What’s more, years of being monitor makes me a brilliant organizer, which will help a lot to keep the exhibition in order. The most important factor is that my related knowledge will undoubtedly help the audience learn more about the unique Chinese art form.
All in all, my sense of responsibility will make me a qualified volunteer. I’d appreciate it if you could take my application into consideration.