Traditional Culture Encyclopedia - Tourist attractions - What do you mean by double or single?

What do you mean by double or single?

These are common expressions in travel.

Double flight means that both round trips are by plane.

Flying solo means that only one trip is by plane.

Sleeper is a kind of sleeper, which is a sleeper for passengers to sleep. There are soft sleeper and hard sleeper.

Similar nouns include "double sleeper" (both are train sleepers) and "single sleeper" (one plane, one train sleeper).