Answer:
carbon and titanium, hope that helps
Explanation:
ANSWER:
C. Red blood cell, heart tissue, circulatory system
BECAUSE:
Red bloods cells make up heart tissues and heart tissues make up the organs in the circulatory system.
Red bloods cells are therefore simpler than heart tissues and heart tissues simpler than the circulatory system.
It can’t be A because blood is simpler than the circulatory system
It can’t be B because nerves and the brain are simpler than the nervous system
It can’t be D because bone is simpler than the skeletal system
Nancy the neuron has just fired an action potential. Now she cannot fire another action potential until she resets her electrical potential. She is in a refractory period. The refractory period starts after the hyper-polarization of the neuron. In this phase the neurons is inhibited of generating further action potentials, and the recovery to resting potential of the neuron membrane begins with the potassium ions slowly leaking into the cell.