Basic meaning
If you want to see places thousands of miles away, you should go to by going up one flight of stairs. If you want to achieve greater success, you must make more efforts.
Edit the source of this paragraph.
Wang Zhihuan, a poet in the Tang Dynasty, wrote "The Heron Tower", "Climb one floor and drive three hundred li". The whole poem is "The mountains cover the day, and the sea drains the golden river. But as long as you go up a flight of stairs, you can broaden your horizons by 300 miles. "
Edit the background information of this paragraph.
Stork Tower: The former site is in Yongji County, Shanxi Province. It is three stories high, with Zhongtiao Mountain in front and the Yellow River at the bottom. Legend has it that storks often inhabit here, hence the name.
The children scrambled to chase the yellow disc and flew into the cauliflower and couldn't find a place.
A poem by Yang Wanli, a famous poet in the Southern Song Dynasty, was included in the fifth grade Chinese textbook of primary school. The whole poem is as follows:
Hedges are sparse and deep,
The flowers at the top of the tree are not shady.
The children chased Huang Die,
Flying into cauliflower is nowhere to be found.
This poem brings people a breath of spring, especially the dynamic description of children and yellow butterflies in the last two sentences, which makes this spring scene vivid. I wonder if readers have thought about it carefully. Why did Huang Die fly to the cauliflower field?
Many people may answer that it is because Huang Die's protective color and yellow cauliflower blend together, making it impossible for children to find and escape. Yes, the answer is correct, but why not the red butterfly (which can fly into the Peach Blossom Garden) or the white butterfly (which can fly into the pear garden), but the Huang Die, which must grow into a yellow protective color? Not many people can answer this question.
In the poem, Huang Die flies into the cauliflower field, and it can be judged that this butterfly belongs to the family Papilionidae. In the adult stage, they only eat the nectar of cauliflower and collect its pollen, but the cauliflower is yellow. Therefore, in order to protect themselves from natural enemies (such as birds), in the long-term evolution process, only the yellow butterfly was retained, and all other colors were eaten by natural enemies, leaving no offspring. Then, shouldn't the unborn Pieris rapae in the cauliflower field be eaten by natural enemies?
This situation generally does not happen. In fact, Pieris rapae only lays eggs in vegetable fields and never lays eggs elsewhere. Rapeseed (including Chinese cabbage, green vegetables, cauliflower, Chinese cabbage and cabbage, etc. ) can synthesize a compound called glyceride, which is the main component of rapeseed oil when it blooms and bears fruit. Pieris rapae is particularly sensitive to this glyceride, and its head antenna can tell where there is rape by sensing the trace glyceride in the air. It is found that where there is rape, there is egg production. The larvae hatched in the second year grow up after eating the leaves of rape, and then pupate into adults-butterflies. We often find a few small Pieris rapae, that is, the baby of Pieris rapae, on the cabbage or cabbage we bought home. When there are many Pieris rapae, pests will rape them, so when farmers spray pesticides to kill them, they will leave residual pesticides in these vegetables, causing vegetable pollution (which can be washed off). But don't blame Pieris rapae too much. Pieris rapae also played a role in pollination in the process of collecting honey and powder, and made an indelible contribution to improving rape yield.
By the way, it can be seen from this poem that the relationship between Pieris rapae and rape has been observed for a long time in ancient China, but these understandings are only observations of the phenomenon. After the separation and extraction of glyceride abroad, it was found that oleic acid (docosahexaenoic acid) in glyceride was a white powder at room temperature, which could be used as a raw material for advanced lubricants, additives and some fine chemicals. Of course, the real secret of this "recent love" has also been discovered. In the early 1980s, Professor Bin Chen, a chemical scientist in China, discovered that there was a high content of intermediate acid in vegetable oil produced in China, and took the lead in extracting a large amount of intermediate acid from vegetable oil. 1984, the author was fortunate to study the extraction process in the Institute of Color Materials of Shanghai University (formerly Shanghai University of Technology) led by him, and personally measured the content of intermediate acid as high as 5 1%. Vegetable oil can't be bought in the supermarket now. Vegetable oil without glyceride is the salad oil we eat today.
During the rapeseed harvest season, if you go to the farmer's house, you will find hundreds of Pieris rapae flying around the rapeseed in the farmer's grain drying field. The scene is beautiful, even spectacular. You may be happy to see it, but you think that so many cabbage butterflies are flying. They are not happy, but they are probably crying sadly-don't touch our food!