How does a balanced chemical equation illustrate that mass is never lost or gained in a chemical reaction?

Label a-f based on the table using c for concentrated and d for dilute

Skills of homo sapiens were found an excavation. the skulls were preserved because the bodies were frozen. so, these fossils are (blank) fossils.the image shows the evolution of skulls beginning 2 to 3 million years ago. based on the image, modern human skulls(blank) ape skulls.

Select the word from the list that best fits the definition the nuclear family into which a person is born or adopted.