The composition of returning to my alma mater after 20 years. Don't imagine

Time flies, the sun and the moon fly like a shuttle. Before, I was a primary school student in grade five. Now I am a 30-year-old adult, and I have become a university professor! Today, I want to go back to my alma mater, Reservoir Primary School. So, I flew from the moon to the earth by express train and came to my alma mater.

"ah! The alma mater has changed a lot in these twenty years! " I exclaimed. I looked around, tall teaching buildings rose from the ground, and the grass on the lawn was green ... how beautiful! I went to the garden at this time and felt that the plants in the garden were a bit strange. How can they shine? It turns out that the flowers in the garden are artificial luminous plants and can also be used as street lamps at night! Moreover, this plant absorbs carbon dioxide ten times as efficiently as ordinary plants. This kind of plant can be seen everywhere in schools, so the air on campus is very fresh. At this moment, I saw several robots. They greeted me: "Hello, I'm Beibei, a little robot guide, and I'm here to show tourists around the school." "Hello, I'm Jingjing, a cleaning robot. I'm in charge of school health. Now, the school has been cleaned spotless by me! " "Hello, I am a nanny robot, silently taking care of the food and shelter of the teachers and students living on campus." What a thoughtful service! Later, Beibei took me to visit the solar underground playground. It says, "This is the solar underground playground of our school. Solar panels are installed on the ceiling, which can save energy. Moreover, the walls and floors of this playground have heat absorption function, which is warm in winter and cool in summer. It also showed me around the classroom, auditorium and gymnasium. ...

Jingjing also took me to the school cafeteria for a sumptuous lunch.

I looked at my watch. It is getting late. It was six o'clock in the afternoon. So I reluctantly left my alma mater and returned to the moon.