Answer: ask your chemistry teacher!
 
        
             
        
        
        
Lithium is in the first column of the periodic table and thus can only form one bond with another atom (its ion is Li+)
Oxygen can form two bonds (as in the dioxygen O2).
Hence if you conbine Li and O it has to be Li2O.
        
             
        
        
        
Colorimetric methods of analysis make use of Color changes in reagents to decipher the concentration of solutions.
Therefore, color completes the sentence 
<h3>Colourimetric analysis</h3>
Generally, Colorimetric analysis is used to know the concentration of a chemical element in a solution while using colour indicators or reagents.
Therefore
Colorimetric methods of analysis are based on having a reagent that changes Color as a function of the concentration of the analyte.
Color
For more information on  Compound
brainly.com/question/704297
 
        
             
        
        
        
A warming climate can cause seawater to expand and ice over land to melt, both of which can cause a rise in sea level. Storm surge on a Louisiana highway shows the effects of rising sea levels. Many people are interested in climate change and how a changing climate will affect the ocean.