This table shows how the number of kingdoms has changed with each major scientist. Which number belongs in the space labeled X?

Which element provides strength to the exoskeleton of clams and oysters

What substance acts to prevent sudden ph changes in bodily fluids?

Antoine manages a number of apartment buildings that use natural gas for heating, cooking, and laundry. the scatter plot shows the correlation between the outside air temperature and antoine's natural gas bill. which type of correlation does the plot illustrate?