Which of the following does not occur within the first four weeks after fertilization? a. the spinal cord and central nervous system are developing. b. the digestive system is developing. c. fingers and toes can move. d. heart and lungs have developed.

A the spinal cord and central nervous system are developing

Only ten amendments were ratified by the states.

People who utilizes the progression principle will ensure their exercise program increases in frequency, intensity, time, and type. the changes need to happen gradually in order to ensure they make gains in their fitness program. a person who doesn't utilize the progression principle can still gain health benefits from exercising, but will not continue to improve in cardiovascular fitness.