What are the characteristics of letters compared with short messages? (Write at least two)

What are the characteristics of letters compared with short messages? (Write at least two) 1 Short messages are sent quickly, but letters are delivered slowly. 2 books are written with credit pens, which can be long or short, and short messages are written with fingertips, with short words.

What are the characteristics of SMS? Write in at least two different formats: letters have a specific format, and text messages don't.

Response time:

The response time of letters should be calculated in days, while short messages are very short;

Save it in different ways.

Length:

Letters are very long, and short messages rarely exceed 50 words.

Different from environmental restrictions.

Content:

Short messages are casual, and letters are formal.

Extension:

Letters are tools for people who are far apart and can't meet for the time being to exchange feelings and thoughts with each other. Letters have a long history and people all over the world use them. Letters play an important role in the history of human communication. Today, mobile phones, telephones and computers are simple and fast communication tools all over the world, and some people are still willing to exchange information by mail. However, due to the arrival of the information age, the format of letters has become diverse, not limited to the original classic format, and some even have no object, that is, there is no preaching and argumentation by the recipient.

What are the characteristics of Android compared with Apple? You see, this group often exchanges Apple App software, but few people exchange Android.

But Android is much better than BlackBerry and Nokia.

It only lost to Apple.

What are the characteristics of the two scientific and technological revolutions? The first revolution had the practical experience of craftsmen and craftsmen, and science and technology were not really combined.

During the second industrial revolution, the new development of natural science began to be closely integrated with the industrial revolution. Science has played a more important role in promoting the development of productive forces, and its combination with technology has made great achievements in the second industrial revolution.

Characteristics of the third scientific and technological revolution:

1. speed-not only a large number of scientific and technological achievements have appeared, but also the speed of transforming science and technology into productivity has been greatly accelerated, and the process of transforming knowledge into material wealth has been shortened.

2. Wide range-various fields of science and technology penetrate each other, and the development of one technology leads to several technological revolutions.

3. Great influence-new technology has become the most active factor in social productivity. Among various factors promoting economic growth, the proportion of science and technology is rising, which promotes the development of productive forces and accelerates the transformation to direct productive forces. Science and technology are closely integrated and promote each other. Various fields of science and technology permeate each other.

What are the characteristics of Sanya compared with Haikou? Haikou is the capital of Hainan and the political, economic and cultural center. It has a long history and began to be the setting of the city in the 1920s. In recent years, some high-tech industries introduced from Hainan have mostly settled in Haikou. Larger enterprises on the island are also in Haikou. Although it is also a tourist city, it does not rely on tourism, and the municipal facilities and residents' living security system are relatively perfect.

Sanya is the only prefecture-level city in Hainan except Haikou, which was built in the 1980s. The port city in the south of Hainan Island is also a famous tourist city, located at 18 degrees north latitude.

The main industries are tourism and real estate, but except for hotels, urban construction is not as good as Haikou. Survive by tourism. Due to the development and construction, there was no land available in Sanya as early as four or five years ago. At present, the so-called Sanya real estate fever reported by the media is actually not in Sanya.

What are the characteristics of geese? (at least 6 geese)

Open classification: biology, flight, nature, animals

Wild geese, also known as wild geese, swans and large migratory birds, are national second-class protected animals. Wild geese are full of enthusiasm, can inspire their companions, and encourage their flying companions with their calls.

It is understood that goose meat is low in fat, cholesterol and protein. More than ten pharmacopoeias, such as Qianjin Shi Zhi and Compendium of Materia Medica, have recorded goose meat in detail: it is sweet in taste, flat in nature, enters the meridians, lungs, kidneys and liver, dispels wind and cold, strengthens bones and muscles, and benefits Yiyang's qi. It is understood that goose down is warm, very light and soft, and can be used as a filling material for pillows, cushions, clothes, bedding and so on. Harder feathers can be processed into fans and handicrafts.

These geese fly in herringbone or zigzag, because they fly all day. It is not enough to rely on the strength of a goose. They must help each other to fly fast and far. When powerful geese flap their wings, a gust of wind blows from the tip of their wings, and when they are sent from bottom to top, they are gently lifted up so that they will not fall behind after a long journey.

Generally, the geese in front are very powerful and experienced. Because the head geese flap their wings to drive the airflow, if they fly in a herringbone or zigzag way, the geese behind them will fly easily without taking many breaks. A low-pressure area will be formed behind the head geese during the flight, and the geese that follow can use this low-pressure area to reduce the air resistance during the flight. It is beneficial to the continuous flight ability of the whole group.

The same principle also exists in track and field sports. In the middle and long distance race, some experienced athletes will not run first, but run closely behind one, because the air resistance to him will be smaller than the first. It's also easier to run.

These geese fly in flocks.

Gus is an excellent air traveler. Every autumn and winter, they fly in droves from their hometown Siberia to the south of China for the winter. The following spring, after a long journey, they returned to Siberia to lay eggs and breed. The flying speed of geese is very fast, which can fly 68 ~ 90 kilometers per hour, and the long distance of thousands of kilometers is only one or two months.

During the long journey, these geese were well organized. They are usually arranged in herringbone or zigzag. When they fly, they keep making "honk, honk" calls. This cry of geese plays a signal role of caring for each other, calling, taking off and stopping.

Then, what is the purpose of keeping the geese in strict and neat formation, that is, the shape of "human" or "one"?

It turns out that this kind of team is very labor-saving to fly. When the geese in front flap their wings a few times, there will be an updraft, and the geese in the back will follow. You can use this airflow to fly faster and with less effort. In this way, one after another, geese naturally form a neat "human" shape or a "one" shape.

In addition, the neat herringbone or zigzag arrangement of geese is also a manifestation of herd instinct. Because it is conducive to defending against enemy damage. Goose is always "captain" by experienced old geese, flying in front of the team. During the flight, the leading geese are physically exhausted, so they often exchange positions with other geese. Young birds and weak birds are mostly inserted in the middle of the team. An experienced old goose always acts as a sentry when stopping by the water to look for aquatic plants. If the lone goose flies south, it is in danger of being eaten by the enemy.

Scientists have found that flying geese in a row can reduce the air resistance of geese behind them. This encourages athletes to stay close behind the leading runners in the long-distance race.

Goose belongs to the family Anatidae, which is the general name of various goose subfamilies and is a large-scale swimming bird. The shape is slightly like a domestic goose, and some are smaller. The mouth is wide and thick, the mouth nail is wide, and there are blunt comb-like protrusions on the meshing edge. Male and female feathers are similar in color, mostly grayish brown with stripes. Wild geese live in groups near the water, usually thousands. During the night, the geese are on the alert around and will call the police if they are attacked. The staple food is tender leaves, fine roots and seeds, and occasionally pecking at farmland grains. Fly back to the north to breed after the vernal equinox every year, and fly to the south for winter after the autumnal equinox. Flocks of geese fly in a straight line or herringbone, which is called "Goose Word". Because the team is neat, people call it "strict array" The flight path of geese is straight. The common geese in China are Hongyan, Douyan and White Goose. The Goose Team consists of 6 or multiples of 6. The geese are a group of families, or a group of families.

Goose is a general term for wild geese, which is characterized by large body, high mouth base, almost the same length as the head, strong dentate process at the edge of the upper mouth, and strong mouth armor, accounting for all of the upper mouth. The neck is thick and short, the wings are long and sharp, and the tail feather is generally 16- 18. Most body feathers are brown, gray or white. * * * There are 9 species in the world and 7 species in China. In addition to white geese, there are also common geese, such as red geese, bean geese, bantou geese and gray geese, which are commonly known as "geese" among the people. The wild goose is one of the well-known birds. When migrating, dozens, hundreds or even thousands of geese always gather together and fly in a line with each other. The ancients called them "strict array". The "Yan Zhen" was led by the experienced "Touyan". When speeding up the flight, the team is arranged in a "human" shape. Once it slows down, the queue changes from "human" to "one", which is an effective measure for long-distance migration. When the wings of the "Touyan" flying in front pass through the air, there will be a weak updraft at the tip of the wing, and the people behind can use this airflow in turn, thus saving physical strength. However, "Touyan" is prone to fatigue because there is no weak updraft available, so in the process of long-distance migration, geese need to change their formations frequently and replace "Touyan". Their movements are very regular, sometimes flying, sometimes singing, and constantly calling "Yi, Yi". Migration usually takes place at dusk or at night. During the trip, people often choose lakes and other large waters to rest and look for fish, shrimp, aquatic plants and other foods. Each migration takes about 1-2 months, and there are many hardships on the way. But they go north in spring and south in autumn and never break their word. No matter where you breed and spend the winter, you always go north and south on time. In ancient China, there were many poems praising them, such as "On the first day of August, geese opened and flew south with frost." Lu You's "Rain Ji Chicken Live Early, the wind is high and the array is oblique"; Wei's "Wan Li people go south, three spring geese fly north" (singing geese in the south), "Red Rock on a moonlit night in Meng Chun, Red Rock on a moonlit night in Qiu Meng", "Lv Chunqiu" and so on.

Compared with carbon monoxide, what are the characteristics of H2 reduction? From the thermodynamic point of view, the reduction ability of H2 is higher than that of CO, but it is opposite below 8 10℃.

From the point of view of reaction kinetics, because the molecular radius of H2 and its reaction product H2O is smaller than that of CO and its reaction product CO2, the diffusion ability is strong. This shows that the reduction reaction rate of H2 is faster than that of CO at both low temperature and high temperature.

What are the characteristics of die forging compared with free forging? Die forging is a method to obtain forgings by plastic deformation of metal under external force and fill the die cavity.

Commonly used die forging equipment includes die forging hammer, hot die forging press, flat forging press and friction press.

Compared with free forging, die forgings have high dimensional accuracy, small machining allowance and more reasonable fiber structure distribution, which can further improve the service life of parts. Die forging has high productivity, simple operation and easy mechanization and automation. However, the equipment investment is large, the forging die cost is high, the production preparation period is long, and the quality of die forgings is limited by the tonnage of die forging equipment, so it is suitable for mass production of small and medium-sized forgings (generally < < 150 kg).

What are the characteristics of the heavy rain described in the essay "Heavy Rain" (at least write down the downpour, Mao Mao rain, Mao Mao rain, rainstorm, storm, spring breeze, rain, storm, rain, rain, rustling rain, Mao Mao rain, misty rain, oblique rain, Mao Mao rain and spring rain bursts)