Three explanation methods are mainly used: listing numbers and giving examples; giving examples and classifying; making comparisons and classifying.
1. List numbers and give examples: Another example is the dahlia, which is native to Mexico and has only eight red petals. The history of artificial cultivation is only two to three hundred years, but there are thousands of varieties with different shapes and colors.
2. Give examples and classify them into categories: For example, peony is a wild original species that took hundreds of millions of years to be created by natural selection. The flowers are single-petaled and the flower color is only pink.
3. Compare and classify: In the spectrum, adjacent to green, the long wave end is yellow, orange, and red, and the short wave end is cyan, blue, and violet. We can say that the flower color starts from green and develops towards the long wave end, from yellow to orange, from orange to red; towards the short wave end, it is blue and purple.
Extended information
Creative background: During the ten years of turmoil, Jia Zuzhang was in adversity. Although he felt helpless at this time, he was unwilling to waste his time. He went alone to rice fields, vegetable gardens, and orchards in the wild to observe the dynamics of plant growth, insect activity, and bird reproduction. At the same time, he also read a large number of scientific and agricultural technology books that could be found at the time. In the six years from 1970 to 1976, *** wrote 50 reading notes.
The practice and reading during this period have accumulated a lot of material for popular science creation after the arrival of the scientific spring, and it was only then that "Why Are the Flowers So Red", which won the first prize of the "New Long March Science Popularization Creation", was produced? 》.
Baidu Encyclopedia - Why are the flowers so red