What are the changes that must be made to a regulator to prepare it for use with Nitrox mixtures whose FO2 does not exceed 40 percent?

What are the three major branches of natural science? • earth and space science, life science, physical science •earth and space science, physical science, chemistry •physical science, life science, chemistry •life science, chemistry, physics

Which of the following electromagnetic waves can create ions?

The excretory system,need answers for all: )