There are only three days in a person's life: yesterday, today and tomorrow. Yesterday is a thing of the past, and tomorrow hasn't come yet. We can't invite yesterday back, nor can we have tomorrow in advance. We can only grasp today. We always think that today is the most important, and it seems to represent our whole life. If you don't grasp it well today, it will become a bad yesterday. Yesterday seems to be a withered yellow flower, not to mention tomorrow. A song of tomorrow seems to be a waste of time, but it is an excuse to be lazy. We should seize today, but we can't give up yesterday, let alone tomorrow. It was yesterday that we climbed to today's steps. Without yesterday, we couldn't have gone to today. Yesterday is an important part of today. Without a beautiful yesterday, there would be no rich and broad today. Without yesterday, today would be more monotonous and thin. What we have the most is yesterday, which has precious wealth, profound knowledge, profound thoughts, superhuman wisdom and material civilization necessary for a rich life. Yesterday is history, recording the trajectory of our life, success and failure, glory and shame, experience and lessons, depression and glory. Educated and guided us like a teacher yesterday. Let us breathe the air of wisdom. Yesterday was a mirror, and we could see the beauty, ugliness, right, wrong, good and evil in the world. Yesterday, like a missionary, he told us how to be a man and led us into a noble moral hall. Yesterday, he told us how to treat death and how to get a new life. Yesterday, we learned to recall, think, cherish, forge ahead and choose. Let us know the meaning of life and death. Tomorrow is an endless time tunnel. Tomorrow is empty and ethereal. But tomorrow is full of hopes, dreams and expectations. Tomorrow is mysterious. Tomorrow contains endless treasures, which need us to dig. There are countless opportunities for us to grasp; There are unexpected miracles waiting for us to create; There are many strange melons and fruits hanging, waiting for us to collect them. So tomorrow is our ideal highland, our happy paradise, our paradise, and the heaven given by God. Tomorrow may be the whole meaning of our life. Without tomorrow, yesterday will be in ruins, without tomorrow, today will be an end. Today is short, erratic, impetuous, changeable and fleeting. Most clearly. Only by making the erratic today precise and concrete today can we create a huge and heavy yesterday and have a brilliant tomorrow. Yesterday is the foundation, today is the action and tomorrow is the plan. Without today, yesterday will not progress, and planned tomorrow will fail. Without today, we can't sail out of yesterday's harbor and reach the other side of tomorrow. Hemingway said, I only know what to do the next day. We can have a rest. If so, yesterday has today's set, today has tomorrow's set. Our today already includes yesterday and tomorrow. Yesterday exists forever. Today and tomorrow will never meet us again, and we will freeze in a fixed yesterday. We are destined to live today, dream tomorrow and die yesterday. So yesterday was our real destination. We just found out yesterday. Today belongs to the present and needs us to cherish it; Tomorrow belongs to the future, let's hope on it.

265,438,000 years ago, the earth was still a wilderness, which we can call nature. Nature exists before our consciousness, and human consciousness has a considerable influence on the existence and development of nature. After a long period of purposeful and conscious productive labor, human beings have undergone great changes in the face of nature, leaving a mark of consciousness everywhere they go. It's really great to explore a way out in nature by hook or by crook!

Yesterday, millions of years ago, small human settlements appeared in the wilderness. Whether it is the caves where people live warmly or the cities where houses and highways are built later, these settlements are obviously different from nature. Everything in the world is developing and changing, and so is human society. From eating blood and drinking blood to the Stone Age, from feudalism to capitalism, the formation and development of "society" is accompanied by "natural death", which is shocking.

100 years ago, the last moderns of the great European explorer, the natural area decreased sharply, which made it a novelty. It is also for this reason that the exploration in Africa aroused the imagination of human beings in the19th century. Entering the real natural world will give you an unusual feeling, which most people who have lived in the artificial environment from coming to leaving this world will never feel.

Today in the 20th century, great changes have taken place in the natural balance. In fact, people can say that nature has disappeared. Wild plants have been cultivated in greenhouses, and wild animals have been raised in zoos and hunting parks. The artificial environment has become a souvenir of the natural landscape that used to abound. However, animals in zoos or hunting parks do not lead a natural life.

Marxist philosophy tells us that any phenomenon will cause other phenomena, and any phenomenon will be caused by other phenomena-human beings' endless demand for nature for their own development directly leads to the imminent "death of nature".

Today, we are surrounded by human beings and their creations, and there are "footprints" of human development everywhere. How about tomorrow? Nature may become a fantasy, a myth and an old dream in people's minds, which will never return.

The world is an interconnected whole. From the inside of nature to the inside of human society, from the inside of human consciousness, from nature and human society to the outside world and consciousness, they are all integrated. People can neither deny the objective connection between a thing and its surroundings, nor cut off the connection between yesterday, today and tomorrow. While reflecting on yesterday and examining today, should we do something for tomorrow?

People who have no long-term worries are bound to have near worries. Mankind has tasted the bitter fruit of the transition to nature. Let's do something today to return "nature" to future generations.

Yesterday's human beings lit the fire that burned nature, and today's human beings are witnessing the death of nature. We don't know what will happen tomorrow. I hope that by then, green will not be a memory of yesterday, and the last drop of water in nature will not be our "tears". I hope the road of yesterday, today and tomorrow is not a natural road of blood and tears.