Answer: B

This question examines the characteristics of time. Test-taking guidance Time refers to the continuity and sequence of material movement, which is characterized by one-dimensionality, that is, the passage of time will never return. The ancients often used wise sayings such as "If time comes, time will never come again", "Opportunity cannot be missed, time will never come again", "An inch of time is worth an inch of gold, an inch of gold cannot buy an inch of time" to illustrate the irreversibility of time and ask people to cherish time.