What should be a possible reason for the demise of Mayan civilization??? Please answer ASAP thank you

Which of the following guidelines should be followed if you have a large spill that is dangerous or beyond your ability to clean up? a) call emergency authorities b) try to keep it quiet so nobody panics c) if the material is flammable, get several buckets of water to dilute it with d) wipe up as much as you can with appropriate rags

To what kinds of messages might the brain respond to keep you balanced on one foot?

There are 25 elements found in living things. how many of these elements are found in some organisms but not all? 1 , 6 , 19 , 25