Typically long pauses in responding are found in schedules.

When water freezes, it . contracts expands

The first generation of offspring from the cross of two parents is called the a.f1 generation b.f2 generation c.short generation d.p generation

Scientists discover two populations of mice on either side of a major river. the two populations have almost identical genes but the mice from one side cannot breed with mice from the other. this is most likely because