The competition between natural selection and natural selection: the survival competition of organisms; Natural selection: natural selection. Creatures compete with each other, and the fittest survive. At first, it refers to the general law of biological evolution, and later it is also used for the development of human society. As objects and attributes; Refers to natural competition.
Struggle for length: long and short: right and wrong. Argue about who is right and who is wrong. It means to care too much about unimportant things. As predicate and object; Used in competitions.
Enter the dragon: Describe fierce struggle or competition. With "into the dragon". As predicate, attribute and clause; A fierce struggle.