A conventional idea is: . Never shared with anyone Popular and common Useless and foolish

The correct answer is: Popular and common.A conventional idea refers to an idea that is widely accepted, commonly held, or generally recognized by the majority of people. It is a concept or thought that is considered to be typical or standard within a particular context or society. Conventional ideas are often based on traditional beliefs, customs, or practices that have been established over time and are widely accepted as the norm or standard.