The second question:

The third question:

The fourth question:

The fifth question:

This part of the extended information mainly examines the knowledge points of numerals:

Two numbers with equal absolute values and opposite signs are opposite to each other. The essence of opposites is that their absolute values are the same. For example, -2 and +2 are antonyms. The letters A and -a are opposites, and the opposite of 0 is 0. Here a is any number, which can be positive, negative or 0.

Characteristics of enantiomers: If A and B are enantiomers, then A+B = 0; Otherwise, if a+b=0, then a and b are antipodal. The antonym of zero is 0. Antiquities appear in pairs and cannot appear alone.

Distinguish between "opposite number" and "quantity with opposite meaning". The "opposite number" is not only the opposite sign of the number, but also the number after the sign must be the same, such as +5 and -5, while the "quantity with opposite meaning" only needs the opposite sign, such as +3 and -7.