Complements means that there is a certain consumption dependency between two commodities, that is, the consumption of one commodity must be matched with the consumption of another commodity. They can be divided into two categories. Ordinary complemens means that there is no fixed proportion of two commodities used at the same time; Complete complements that two commodities must be used at the same time in a fixed proportion.
According to the above definition, which of the following options is correct?
Digital photo coder and film are common complements