When a person eats, the brain signals the stomach to start breaking down the food. Which two 1 point systems are involved in this process?*
Circulatory and respiratory
Nervous and digestive
Digestive and excretory
Muscular and digestive

Nasa scientists must work together to make sure that everything is correct and accounted for when launching a shuttle. besides a physicist, what other type of scientist would be in making sure that the shuttle has the appropriate type and amount of fuel to reach its destination?

In a cladogram' when does a group of organisms branch off

9. the history of life on earth is recorded in