What kind of group ceases to exist if even one member leaves the group?

dyads

Explanation:

A dyad is a kind of group that ceases to exist if even one member of leaves the group.

Such groups consists usually of two people.

A dyad is used in sociology to refer to a group of two peopleIt can be a brother and a sisterSuch groups can be terminated when one member of the group pulls out or dies. Dyads are the simplest group structures known. Members of a dyad can be linked by education, romance, business, e.t.c

Currently, as of february 2016, an american traveling in france would be by the exchange rate. the weakness of the euro and the strength of the us dollar means that items in france cost less to an american than they otherwise would. of course, if this trend reverses and the us dollar weakens and the euro strengthens, such as was happening in early 2008, an american traveling in france would have an adverse experience because items would cost relatively more.