I believe that everyone will inevitably come into contact with composition, especially as an explanatory text of a common style. Explanatory text makes people have a scientific understanding of the shape, structure, nature, types, causes, functions, relationships or concepts, characteristics, sources, evolution, similarities and differences of things through the explanation of objective or abstract things. How to write an explanatory article to highlight the key points? The following is my description of ginkgo biloba for reference only. Let's have a look.

Ginkgo biloba 1 Ginkgo biloba, also known as Gongsun Tree, is the longest-lived tree species in fruit trees. There is one in front of my house. Its trunk is thick and tall, and its branches and leaves are particularly lush. Its leaves are like a delicate little fan. Ginkgo biloba is a dioecious plant, both sexes are planted on short branches. Most of these short branches germinate and grow from the buds in the middle and lower parts of long branches. The growth of this short branch takes 2-3 years, and more than 5-6 leaves can form flower buds. The top of the short branch is a large mixed bud, and the short fruit has a strong ability to bear fruit continuously, which can generally reach about 25 years. Short branches over 30 years old still have the ability to bear fruit, but short branches over 3 years old and below 15 years old have the best ability to bear fruit, and begin to weaken after 15 years old.

The extension ability of fruit branches is very weak, and the annual growth is only 0.2 ~ 0.3 cm, but branches can also grow after the central growth point suffers from * * *; After the terminal buds of short branches are damaged or dead, dormant buds on short branches can germinate to form new short branches.

On a long branch, several short branches can be formed in the same year, and their growth, fruiting ability and weakening time are the same except for the same age. Therefore, pruning is not necessary before the senescence of short branches, that is, when the fruiting ability of short branches decreases and needs to be updated, it is not necessary to update and prune each short branch one by one, just update the branches of the same age. This is the uniqueness of Ginkgo biloba from other fruit trees. It can be seen that ginkgo tree has stable fruiting branches, small growth, strong continuous fruiting ability, easy cultivation and easy drying up.

Ginkgo biloba has almost no developing branches and is not as sensitive to pruning as apples and pears. Long branches can naturally produce short branches, so pruning is simpler. Pruning is mainly to cultivate backbone branches, allocate and adjust the result branches, straighten out the subordinate relationship and adjust the balanced growth of branches.

The short fruiting branches of Ginkgo biloba are germinated from the buds on the long branches. Therefore, the stronger the long branches grow, the more short branches germinate and the better the results will be. Therefore, attention should be paid to selecting and retaining long branches when pruning; The hidden buds of ginkgo trees have a long life and are easy to shade, and they are easy to blossom and bear fruit after germination. Therefore, it is also very convenient to update ginkgo trees. Inside the crown, under the main branch, it is not easy to be bald. This is also the particularity of ginkgo trees.

Ginkgo biloba 2 Ginkgo biloba, commonly known as ginkgo tree and Gongsun tree, first appeared 300-400 million years ago and is a very old tree species. Later, the earth suddenly became cold, and most ginkgo plants became extinct. It's just that our superior natural conditions in China have miraculously preserved this species. Jiangsu, where Taizhou is located, is located in the middle and lower reaches of the Yangtze River with a mild climate, which is an ideal place for the growth of ginkgo trees, especially Taizhou, which is very obvious.

Ginkgo biloba leaves are beautiful and change with the seasons. Every season presents different colors, and each color is very attractive.

In spring, the ginkgo tree sticks out a little green head. They danced in the breeze; In the sun, they shine with the brilliance of life.

In summer, the wind is sunny, and the fan-shaped leaves make rustling sounds, like experienced drummers and wind chimes with beautiful notes. The leaves are so green and bright, it seems that oil will flow out at a touch.

In autumn, "butterfly" flies down from the tree and lies beside the roots. They slept so comfortably that they seemed to have returned to their native land; They danced with the wind one by one, as if reciting a newly created poem: "Red leaves floating in the autumn wind dance on the stage like autumn". This scene is like a picture scroll. Whenever we see this painting, people can't help admiring the great painter nature.

There are almost no leaves on ginkgo trees in winter, which is particularly desolate. But there are always a few "tenacious" leaves on it, which are extremely tragic.

The fruit of ginkgo tree is commonly known as "Ginkgo biloba". Ginkgo biloba is delicious and nutritious. I prefer to eat fried in the microwave oven. When the sound of "Zizi" came to my ears, I was satisfied although I didn't eat it.

I like ginkgo tree, like its leaves, like its fruits, like everything about it!

I like ginkgo tree best, because it is my favorite tree.

I remember once in autumn, I watched the golden leaves of a tree shining in the sun and couldn't help but sigh: "Wow, this tree is really beautiful!" " "

On my way to school, there is a row of ginkgo trees. Rows of ginkgo trees are tall, with thick trunks standing upright. Don't think it's a bare tree. Its trunk is covered with many trunks, and the dense branches are surrounded by golden leaves, like a feather duster. Seen from a distance, it stands there like a giant. A section of the trunk on the ground is painted with lime, just like wearing white socks, which is both beautiful and moth-proof!

Late autumn is its most beautiful time. At this time, the leaves of the tree turned golden, and they formed a huge golden crown. Autumn wind blows, leaves fall from the branches, just like small paratroopers falling from the season, dancing like golden butterflies. The car passed by, and the leaves rolled with the wheels, like a race.

I picked up a leaf and observed it carefully. The leaves are very smooth, and a vein is clearly visible, like fireworks set off during festivals. Petiole up, like a small sailboat! Smell it, and it's mixed with a faint fragrance.

Ginkgo tree is a beautiful scenery at any time. I love ginkgo trees!

Ginkgo Expo 4 Ginkgo biloba

Ginkgo biloba has a very old and long history. As early as 270 million years ago, it appeared on our planet. About 65438+ billion years later, Ginkgo reached its peak. Large tracts of ginkgo forests are found almost all over the world, as common as dinosaurs living in the same era. Therefore, people also call it a dinosaur in the plant kingdom. But in later years, Ginkgo biloba, like many great empires, gradually lost its dominant position from prosperity to decline. In Tertiary, the climate on the earth has changed greatly, and the mountains are constantly uplifting. Ginkgo biloba was forced to withdraw from the historical stage of biology in the competition with new plants. Only in a few areas, protected by the unique geographical environment, can a small number of Ginkgo biloba survive. They have become a rare thing in the plant world and a living fossil of plants in the minds of scientists.

Compared with other plants, Ginkgo biloba grows very slowly. In general, it takes l5-20 years to plant its seedlings, and some even take 3040 years. As the saying goes, my father-in-law planted trees and my grandson ate fruits, so people gave it an image nickname Gongsun Tree.

With such a slow growth rate and such a late fruiting age, there must be a long life to adapt. That's right. Ginkgo biloba is indeed a typical long-lived tree species. The oldest ginkgo tree found at present grows in Ding Lin Temple on the northern slope of Shandong Fulai Mountain. It is said that it is over 3,000 years old, and it is still full of fruits today.

So, why can ginkgo live so long?

Botanists have found in their research that all long-lived ancient ginkgo biloba have extremely developed roots, which are conducive to resisting various adverse environments in the depths of the ground. In addition, because ginkgo grows slowly and needs less nutrients, it is entirely possible to live in one place for hundreds or even thousands of years. Another reason for ginkgo's longevity is that there are few pests and diseases. This is because there is a substance called vinyl aldehyde and a variety of organic acids in Ginkgo biloba, which has strong antibacterial and insecticidal effects, so Ginkgo biloba is rarely attacked by pests and diseases.

Ginkgo biloba not only has scientific research value, but also has great economic use. Its fruit is called Ginkgo biloba, and its flesh is soft, smooth and fragrant. It is made into candy or other food, which is delicious and nutritious. Ginkgo biloba can also play an important role in gardens. Because it has special resistance to many kinds of diseases and insect pests and can resist the pollution of black smoke, dust and toxic gases in the city, it has some advantages over other plants as a street tree in the city. Ginkgo biloba leaves are unique in shape and turn orange in autumn, which is very delicate and lovely and has high ornamental value.

(The author's anonymous article has been deleted)

1. Can the words added in the following sentences be deleted? Why? (3 points)

About 65438+ billion years later, Ginkgo reached its peak.

2. Why do people call Ginkgo biloba a dinosaur in the plant kingdom? (4 points)

3. The underlined sentences in the text are explained by _ _ _ _ _ _ _ _ _.

Its function is. (4 points)

Please summarize the reasons for the longevity of ginkgo trees. (4 points)

5. Why should ginkgo trees be street trees? If you were asked to choose street trees for the roads in your hometown, what kind of trees would you choose (except ginkgo trees)? Please provide a justification for the answer. (5 points)

Answer:

1 ... cannot be deleted. (1) is an approximate value, indicating an estimate, while ginkgo trees have a long history and cannot be accurately calculated, so they can only be said to be approximate values. The use of approximation reflects the accuracy of explanatory language. (2 points)

2. Ginkgo biloba has a long history, (2 points) is as common as dinosaurs living at the same time. (2 points)

3. Column number, (1 min) and example (1 min). Accurately and concretely explain that ginkgo tree is really a long-lived tree species. (2 points)

4. Have a developed root system; Slow growth; Need less nutrition; Rarely attacked by sick pests. (65438+ 0 point per point)

5. The first question: (3 points) It is resistant to pests and diseases, pollution and strong ornamental. Question 2: (2 points) Write a tree name, which conforms to the characteristics of the tree.

Label: descriptive ginkgo biloba