Which statements best describe fossils? Check all that apply.
They only show evidence of living species
They are the preserved remains or evidence of organisms.
They can show how organisms have changed over time.
They do not show relationships between organisms.
They can help scientists identify extinct species.

Iknow #2 is d. i just need to know why

1.aluminum chloride (alcl3), and sodium hydroxide (naoh) can react to form aluminum hydroxide (al(oh)3) and sodium chloride (nacl).    you have 13.4 g of aluminum chloride and 10.0 g of sodium hydroxide. answer the following questions: •what is the balanced equation for this reaction? •if you use all 13.4 g of aluminum chloride, how many grams of aluminum hydroxide can be formed? work must be shown to earn credit •if you use all 10.0 g of sodium hydroxide, how many grams of aluminum hydroxide can be formed? work must be shown to earn credit •how many grams of aluminum hydroxide will actually be made?     which reagent is limiting? explain your answer.

The chart shows the bid provided by four contractors to complete a job. which contractor is the most cost-effective?