The meaning of this sentence is that the whole is composed of parts, and the formation of the whole function cannot be separated from some original functions. "Life * * * is the material basis for human survival and development", part of it is a part of the whole, and part of it will no longer have some functions without the whole. The whole and the part are interdependent.
We should realize that landscape, forest, field and lake are the same life. The lifeblood of man lies in the fields, the lifeblood of fields lies in water, the lifeblood of water lies in mountains, the lifeblood of mountains lies in soil, and the lifeblood of soil lies in trees. Humans can use and transform nature, but in the final analysis, it is a part of nature. We should cherish nature and not be above it.