Why is a shell considered to be biotic

Sarah is sitting at the top of the slide in the schools playground. which will increase sarah’s kinetic energy a- an additional child is added to the top of the slide. b- sarah is pushed and moves down the slide. c- sarah climbs down the ladder and off the slide. d- the ladder is moved to the other side of the yard.

How can you approximate the number of calories required to keep you in energy balance?

How can a geological time scale best be reconstructed? a) comparing vestigial structures in living species b) comparing homologous structures in living species c) examining homologous structures in fossil remains d) examining the written records of scientists from past cultures