Maria believes that high doses of caffeine speed up a person's reaction time. In order to test her hunch, she has five friends each drink three 8-ounce cups of coffee and then measures how quickly they are able to push a button when a tone is sounded. What is wrong with Maria's research strategy?

Maria is missing a control group.

Explanation:

For Maria's experiment to be accurate, she needs to have a group of people that have not drank coffee. She will then be able to compare the experimental group to the control group for more accurate results.

the plates spread at mid-ocean ridges (they are divergent plate boundaries) which allows magma to rise through the weakness between the plates. the magma then emerges as lava from the boundary and cools, creating a new crust.