What was one of the ways thy people of ancient times classified plants and animals

What is the answer for the complicated molecules that make up living things usually contain carbon. why is carbon so important in these molecules?

Linda and julia are trying to determine whether their ideas are scientific or pseudoscientific. linda's idea is free of bias. julia's idea gives the same result when tested repeatedly. which statement is correct about linda and julia's idea?

18. which statement about cancer is true?