Second, the clearance sale (in a mathematical term): absolute value.

Explanation:

"2, 4, 6, 8, 10" is unique because it has even numbers and no odd numbers.

The clearance sale means that the price has dropped and it is more worth buying than usual, so it is "absolute value".

Related introduction:

1. Coincidence: It means that although it is rare, there is not only one, but also one that can be paired (often used in a derogatory sense).

Source: Mr. A by Liu Bannong: "Mr. Wang and this can be said to be unique."

2. Absolute value: absolute value is the distance from a point corresponding to a number on the exponential axis to the origin. Absolute value is closely related to concepts such as size, distance and norm in various mathematical and physical environments.

Extended data

The riddle style can be roughly divided into four types: mainstream, folk and elegant and popular.

1. Mainstream: Most of these puzzles are created in a certain period and occasion, and they are specially created for a specific need. Its characteristics are prominent theme, serious content, strong pertinence and remarkable effect. Although the themes are different, they all have mainstream characteristics. Here are some examples to illustrate:

China is taking off. The answer is: sublimation.

Second, folk: folk guesses are based on common and familiar things among the people. The language of crossword puzzles is catchy and easy to remember and pass on.

Third, elegance: elegant style, also known as "the meaning of a calligrapher." This kind of riddle pays attention to literary talent, is full of books, and is mostly riddled with allusions, or draws on famous sentences of predecessors, and pursues appropriateness and naturalness in closure. It's hard to guess and answer. Examples are as follows:

Frostbird wants to have a peek first. (Guess The West Chamber) Answer: I dare not go on.

4. Popularity: This riddle has fewer obstacles to guess. Because most riddles come from life, they use popular language. Even in a word, it is approachable. In terms of fastening, even if there are other solutions, it is only a method of polysemy of Chinese characters. For example:

The sky is full, and the pavilion on the ground is Fiona Fang. (Guess a polite expression) Answer: Good sir.

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