Answer: A. Single column installation and D. Wall-mounted installation
Answer analysis:
When discussing the installation methods of LED display screens, we must first understand that LED display screens require diverse installation methods due to their wide range of application scenarios (such as outdoor advertising, stadiums, commercial centers, etc.).
Now, let's analyze the options in the question one by one:
A. Single column installation: This method is usually used for large outdoor LED display screens, such as billboards beside highways. The single column structure is stable and can support large and heavy display screens, ensuring its stability and safety in various weather conditions.
B. Double column installation: Although this option is similar to the single column in physical structure, the double column is usually used in occasions that require greater support and stability, or pursue a certain symmetrical beauty in design.
However, not all LED display screens will use double column installation, which depends on the specific application scenario and requirements.
C. Wall embedded installation: This method is to embed the LED display screen into the wall, leaving only the display surface exposed. It is usually used in indoor environments, such as shopping malls, exhibition halls, etc., which can save space and make the overall look more neat and beautiful. But this method is not suitable for all walls or all LED screens, because it requires the wall to have sufficient thickness and structural strength to support the screen.
D. Wall-mounted installation: This is another common indoor LED screen installation method.
Unlike embedded installation, wall-mounted installation is to hang the screen directly on the wall without embedding it inside the wall.
It is more flexible, suitable for a variety of wall and screen sizes, and relatively simple to install and maintain.
Now, let's get back to the question itself. The question asks about the "main" installation method of LED screens. Among the four methods, single-column installation has become a very important installation method because it is suitable for large outdoor screens and has a stable structure.
Wall-mounted installation is equally important because of its flexibility and wide application scenarios (especially indoor environments).
In contrast, although double-column installation has its specific application scenarios, it is not adopted by all LED screens; and wall-embedded installation is limited by the structure and thickness of the wall, and is not applicable in all cases.
In summary, the "main" installation methods of LED screens should include those that are widely used, stable in structure, and highly adaptable.
Therefore, option A (single column installation) and option D (wall-mounted installation) are more reasonable answers.
However, since the question requires "which of the following are mainly divided into", considering that "mainly" may mean the most commonly used or most representative method, and choosing from the options given in the question, we can think that options A and D together constitute the main installation methods of LED display screens.
But strictly speaking, if you have to choose a statement closest to "mainly", you may tend to choose option D, because wall-mounted installation is not only suitable for indoor environments, but also can be flexibly adjusted as needed, with higher versatility and adaptability. However, in the context of this question, we usually regard both A and D as correct answers.
Therefore, the final answer should include A, single column installation and D, wall-mounted installation. However, since the options usually require single or multiple selections (clearly stated), if this question is a multiple-choice question, select A and D; if you must select a single choice, judge according to the specific requirements and context of the question. But here, we are more inclined to think that both A and D are correct answers.