How to distinguish items from A, B, C, D?

A, B, C, D, and E are Chinese heavenly stems, and are usually used to mark time, order, or classification. To distinguish between items of A, B, C, D, etc., it is necessary to understand their respective characteristics and classification. Here are some common items that indicate A, B, C, D, and E:

A: Crustaceans, such as turtles, crabs, etc.

B: Woolen fabrics and fur products. In addition, there are also second-division football teams, which refer to football teams that should have won the ranking of first-division teams, but for various reasons were relegated to second-division teams.

C: Polymer materials, plexiglass, etc. In addition, Category C housing refers to commercial buildings such as commercial, tourism, and entertainment facilities.

D: Household appliances, electronic products, etc. In addition, Grade D dwellings refer to all types of dwellings that are used for residential purposes only, and the number of people living at the same time does not exceed the standard four persons.

E: Utensils and materials used in the manufacture of ancient celestial instruments and musical instruments, Chinese herbal medicines, Wuji pills, etc. In addition, hepatitis E is a type of hepatitis virus.

To sum up, the distinction of A, B, C, D, and E is mainly based on their characteristics, uses, and classification methods.

1. Usually the fire hazard in production and the fire hazard in storage are classified into five categories, that is, A, B, C, D, etc. 2. The specific criteria for discrimination are in the building design fire protection code 3, and the building design fire protection code can be found from the library, address.

According to the Code for Fire Protection Design of Buildings, the fire hazard is divided into the above categories.

A, B, C, and D represent the following substances: Zen shouting.

Class A: (1) flammable liquids (low flash point, medium low flash point): ether, cyclohexane, ethane, acetone, acetaldehyde, ethyl formate, 2-methylfuran, diethylamine, 2-butanone, methylisopropylene (methyl) ketone [inhibited], ethyl-n-butyl ether, chloromethyl methyl ether, coal tar, 2-methyltetrahydrofuran, n-propyl formate, isobutyl formate, methyl acetate, ethyl acetate, n-butyl acetate, solvent benzene, ethylbenzene, ethanol (anhydrous-propanol, etc.)

(2) Spontaneous combustibles, flammable materials when wet: white manuscript phosphine, sodium dithionite, potassium dithionite, etc.

Class B: amino resins, paints containing secondary flammable solvents, unsaturated polyester resins, glycol acetate ether.

Polyurethane resin, styrene (inhibited), n-butyl acrylate (inhibited, 2,4-trimethylbenzene.

Propylene glycol ether, ethylene glycol methyl ether, ethylene glycol ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, ethylene glycol acetic acid methyl ether.

2-methyl-1-propanol, n-butanol, asphalt primer, etc.

Class C: flammable liquids with a flash point higher than 60.

A: Barium hydroxide.

Brother Yi Jingzi: Sodium hydroxide.

C: Dilute salt bright acid.

D: dilute nitric acid.

and litmus turn blue, so A and B are bases, and B can produce white precipitates, B cannot, so it is a cationic relationship, and the white precipitate may be Baso4 or BaCO3 precipitates, so A is barium hydroxide, and B is sodium hydroxide.

and litmus turn red, so propylene is acid, plus agno3 propylene can generate precipitate, the precipitate can be known to be agcl, so propylene contains cl-, so propylene is dilute hydrochloric acid, butyl is dilute nitric acid.

C: dilute hydrochloric acid, D: dilute nitric acid, B: sodium hydroxide solution, A: barium hydroxide solution.

A lead defamation: Yu Bi cuo

B: H2SO4

C: CuSO4

D: Cu(OH)2

E: Na2SO4

F: Huai lacks baso4

A, B, and C both point to D, then D is magma, and magma can only be converted into magmatic rock, so B is magmatic rock, metamorphism can only act on metamorphic rock, so C is a metamorphic rock, so A is a sedimentary burn rock.

Sedimentary rocks, magmatic rocks, metamorphic rocks, magma.