1. ** Shen (now "Shen") **:
- Ancient Shen, its land has many uses. In terms of transportation, because it is often at the waterway, it is a key node of water and land transportation. According to the "Shuijing Note", there are frequent boats and boats around Shen, which are the place for goods transshipment and personnel passage. The goods from all over the world gather here and then disperse to various places. It is an important hub for regional trade circulation.
- In military defense, Shen's terrain is dangerous and the city is strong. In ancient wars, Shen was often a must-have for soldiers, with strong city walls, fortresses and other fortifications built to protect one side's territory and safeguard the security of the country or region. Many battles took place here, and its military strategic position was pivotal.
- From the perspective of agricultural production, the soil in Shenyang is fertile and the water is abundant, which is conducive to the growth of crops. The surrounding vast farmland is planted with a variety of crops such as millet and wheat, which provides abundant food for the local residents and supports the reproduction and development of the regional population.
2. ** Jiang **:
- The river, as an important water system, is the main artery of transportation. "Yugong" records that ships shuttle on the river surface, carrying timber, ores and other resources upstream, and downstream transporting various industrial products to various places, promoting the exchange of materials between different regions.
- In terms of agricultural irrigation, the many tributaries of the river extend to vast fields, providing ample water sources for farmland. Farmers divert water from the river for irrigation, making large tracts of land into fertile fields, ensuring a bumper harvest of grain, and is the foundation for agricultural economic prosperity.
- The river is also a treasure house of fishery resources. Fishermen live by the river and fish as their business. The rich fish resources in the river not only meet the dietary needs of local residents, but also circulate to other regions through trade, becoming an important economic industry.
3. ** River **:
- The river connects north and south in transportation and communicates east and west. In ancient times, water transportation relied on rivers. A large amount of grain, grass and materials were transported to the capital and border areas through rivers to maintain the operation of the country. Such as the Sui and Tang Dynasties Grand Canal, which was based on rivers such as the Yellow River, strengthened the economic and cultural exchanges between the north and the south.
- For the rise and development of cities along the coast, rivers played a key role. Rivers provided abundant water sources, attracted population gatherings, and developed industries such as commerce and handicrafts. Like Bianjing, which is located in the Yellow River Basin, has become a prosperous metropolis by virtue of the convenience of rivers.
- In the construction of water conservancy projects, rivers provided the basic conditions for the implementation of projects. The ancients built dams, sluices and other water conservancy facilities to regulate river flow, both flood control and irrigation. For example, Dujiangyan used the water of the Min River skillfully, which created the wealth of the Chengdu Plain.
4. ** Bottle gourd **:
- Bottle gourd has a wide range of uses in diet. Its tender fruit can be used as a vegetable, cooking in various ways, or stir-fried, or boiled, or stewed, with delicious taste and rich nutrition. It is a common delicacy on the people's table.
- After ripening, bottle gourd can be processed into various utensils. Saw it open and it can be made into a scoop for scooping water and holding things; after drying, it can also be made into a container to store food, seeds and other items, which plays a practical function in daily life.
- In ancient cultures, bottle gourd also has special symbolic significance. " In the Book of Songs, "there are bitter leaves, and the economy is deeply involved". Bottle gourd is often given the meaning of marriage and love, which carries the rich cultural emotions of the ancients.

Mercury, bromine, gallium, and cesium each have specific physical properties.
Mercury is a liquid metal at room temperature, with silver flickering and flowing freely. Its melting point is very low, about -38.87 ° C, and its boiling point is only 356.6 ° C. The density is quite high, reaching 13.59g/cm ³, so it can gather into drops on a plane and roll agile. Mercury has good electrical conductivity and is widely used in many appliances such as electrical instruments. However, it is toxic, and vapor inhalation or skin contact can cause damage to the human body. It should be used with extreme caution.
Bromine is the only non-metallic element that is liquid at room temperature and pressure. Its color is red-brown, has a strong irritating odor, and is highly corrosive. Melting point -7.2 ° C, boiling point 58.8 ° C. Bromine is volatile, and its brown vapor is often seen rising in the air. The density is 3.119g/cm ³, soluble in water and a variety of organic solvents, and widely used in organic synthesis, medicine, pesticides and other fields.
Gallium, the melting point is extremely low, only 29.78 ° C, slightly higher than normal temperature, placed in the palm of the hand, the body temperature can melt it into a liquid state, like a magic trick. The boiling point is extremely high, up to 2403 ° C. Its solid is soft and has a metallic luster. Although the conductivity of gallium is inferior to that of common metals, it has an indispensable position in the field of semiconductor materials, such as gallium arsenide and other compounds, which are widely used in electronic devices.
Cesium, soft as wax, silver white and slightly golden in color. The melting point is only 28.44 ° C, and it is also very easy to melt. Its chemical properties are extremely active, and it reacts violently when exposed to water, even causing an explosion. Cesium has excellent photoelectric effect and can quickly convert light into electricity, so it plays a key role in photoelectric tubes, atomic clocks and other instruments. Atomic clocks have extremely high timing accuracy due to the characteristics of cesium, providing accurate time benchmarks for many fields of modern science and technology.

1. Mercury is a liquid metal with a silver flowing state at room temperature. It is heavy and highly volatile. It can gradually turn into mercury vapor in the air, which is highly toxic. Mercury has relatively stable chemical properties and is not easy to combine with common gases such as oxygen at room temperature. However, when heated, it can react with oxygen to form mercury oxide. And mercury can dissolve many metals to form amalgams. This property makes it widely used in ancient alchemy and some traditional processes.
2. Bromine is the only non-metallic element that is liquid at room temperature and pressure. Its color is red-brown, with a strong pungent odor and is extremely corrosive. Bromine is chemically active and highly oxidizing, and can react with many metals and non-metals. For example, when it encounters sodium metal, it can react violently to form sodium bromide. In the field of organic synthesis, bromine is often used as an important reagent and participates in many reactions.
3. Gallium, the melting point is very low, slightly higher than room temperature. If held in the hand, it can be melted by heat. Its chemical properties are relatively active, and it can react with acids and bases. When interacted with dilute hydrochloric acid, it can generate hydrogen and gallium chloride. Gallium is widely used in modern science and technology, such as the preparation of semiconductor materials, due to its unique chemical properties.
4. Cesium, soft in texture, silvery white in color, and has extremely high chemical activity. In contact with water, an explosive reaction occurs, generating cesium hydroxide and hydrogen gas. This reaction is violent and releases a lot of heat. Cesium easily combines with oxygen and is rapidly oxidized in the air, so it usually needs to be stored in a special environment to isolate air and water. Because it is extremely sensitive to light, it has important applications in fields such as optoelectronic devices.

1. ** Method of mercury **:
- The ancient method of mercury is mostly made of Dansha as raw materials. "Baopuzi", Dansha is made of water, and then turned into Dansha. That is, Dansha (mercury sulfide) is added in a dense container. Mercury sulfide decomposes mercury and sulfur, and mercury evaporates and condenses to obtain water. Its reverse formula is\ (HgS\ stackrel {\ Delta }{=\!=\!=} Hg + S\).
- To prevent mercury from evaporating and escaping, the ancients often placed it cleverly. For example, use a bamboo tube or a dense crucible, cover the crucible with a container to collect mercury vapor and wait for it to cool.
2. ** Method **:
- The main raw material is vulcanized (vulcanized). First, it is baked, vulcanized and oxidized, and the reverse formula is\ (2PbS + 3O_ {2}\ stackrel {\ Delta }{=\!=\!=} 2 PbO + 2SO_ {2}\).
- Then use charcoal and other original oxidation to make it original gold, and the reverse formula is\ (PbO + C\ stackrel {\ Delta }{=\!=\!=} Pb + CO\ uparrow\) or\ (PbO + CO\ stackrel {\ Delta }{=\!=\! =} Pb + CO_ {2}\). The ancients mostly used crucibles or easy stoves to do this operation, and it is very important to control the heat.
3. *** Method **:
- The raw materials are mainly stone (such as red stone\ (Fe_ {2} O_ {3}\), magnetic material\ (Fe_ {3} O_ {4}\)), coke and limestone.
- The first coke is burned in oil to provide high temperature, generating carbon monoxide, and the reverse type is used to generate\ (C + O_ {2}\ stackrel {}{=\!=\! =} CO_ {2 }\) ，\( CO_ {2} + C\ stackrel {high }{=\!=\!=} 2CO\).
- carbon monoxide in the original stone, such as\ (Fe_ {2} O_ {3} + 3CO\ stackrel {high }{=\!=\!=} 2Fe + 3CO_ {2}\). Limestone decomposes into oxide and carbon dioxide at high temperature, and the oxide in the stone (such as silicon dioxide\ (SiO_ {2}\)) is reversed to form slag, and the reverse formula is\ (CaCO_ {3}\ stackrel {high }{=\!=\!} =} CaO + CO_ {2}\ uparrow\),\ (CaO + SiO_ {2}\ stackrel {high }{=\!=\!=} CaSiO_ {3}\). In ancient China, it was used to improve the performance of the drum and promote the reverse process.
4. ** method **:
- ** fire method **: to vulcanize the raw material (such as\ (Cu_ {2} S\)). Bake first to make part of the vulcanization and oxidation, and reverse the formula\ (2Cu_ {2} S + 3O_ {2}\ stackrel {\ Delta }{=\!=\! =} 2Cu_ {2} O + 2SO_ {2}\).
- and oxidized vulcanization is not reversed. The reverse formula is generated, and the reverse formula is\ (2Cu_ {2} O + Cu_ {2} S\ stackrel {\ Delta }{=\!=\!=} 6Cu + SO_ {2}\ uparrow\).
- ** method **: As early as in the "Huainan", there is a "Zeng Qingde". That is, put the sulfuric acid solution into the sulfuric acid solution, set out, and the reverse formula is\ (Fe + CuSO_ {4 } =\!=\! = FeSO_ {4} + Cu\). This method is easy to operate, low cost, and widely used in ancient times.

When storing and transporting mercury, bromine, liquid bromine, and iodine crystals, there are many key points to be paid attention to.
Mercury is a liquid at room temperature and is volatile and highly toxic. When storing, use a sturdy and sealed container to prevent leakage. To reduce its volatilization, a layer of water can be covered on the mercury surface. At the same time, it should be placed in a cool and well-ventilated place, away from heat and fire sources. The volatilization of mercury is exacerbated by heat. When transporting mercury, the packaging must be tight and marked with significant toxicity. In the event of mercury leakage, it should be quickly dusted with sulfur powder, because mercury and sulfur can form stable mercury sulfide to reduce toxicity and volatilization.
Bromine, a dark reddish-brown liquid at room temperature, is highly volatile, and highly corrosive and toxic. Storage of bromine requires glass bottles with frosted glass stoppers, not rubber stoppers, because bromine can corrode rubber. The bottle should be sealed with an appropriate amount of water to reduce bromine volatilization. Store in a low temperature and dark place, because light and high temperature will accelerate bromine volatilization. When transporting bromine, the packaging should be tight to prevent bromine leakage caused by damage to the container. If it accidentally touches the skin, it should be rinsed with a lot of water immediately, and then wiped with alcohol.
Liquid bromine has similar properties to bromine, and the storage and transportation points are similar. Because of its strong volatility, water sealing is particularly important. Special attention should be paid to shock prevention, collision prevention, and packaging damage during transportation.
Although iodine crystals are solid, they are easy to sublimate. When storing, use a sealed container in a cool and dry place to prevent heat and moisture. When transporting iodine crystals, also ensure that the packaging is well sealed and avoid mixing with substances that can react with them.
To sum up, mercury, bromine, liquid bromine, and iodine crystals should be stored and transported according to their characteristics. Care should be taken in packaging, storage environment, labeling, etc. to ensure safety and prevent leakage and accidents.