Who are the people who give silently like street trees? Such as: cleaners and the like, be specific and urgent ~

Cleaners get up early every day, clean the road for us, and welcome the first ray of sunshine for us. Just like street trees, they never complain, and have been quietly making their best efforts for our environment. There are many people like them in life, such as traffic police, who always maintain order in the middle of the road, whether it is hot or heavy rain. People's soldiers fight floods and rescue. Volunteers have been showing the charm of China to people all over the world, but Dont Ask For Help will repay them, hoping that the image of China people will enjoy a high reputation in the world. They have been unknown, but everywhere, and have been working hard for our life and our future!

I thought of it temporarily. Please advise if it is not good!