Describe 2 psychological and 2 biological effects that must be overcome by an astronaut on a two-week space mission.

Hurry which of these is true about index fossils? a) are very scarcely found b) used as guides in relative dating c) found in the youngest layer of the rock d) used as reference points in absolute dating

What advantages does a pedigree have over a written passage?

Which of the follow describes a disadvantage secondary sources have compared to primary sources?