1. Which of the following is true of a chemical reaction? a. Only physical changes occur.
b. New substances must form.
c. Only changes of state occur.
d. Chemical properties remain the same.

Select each correct answer. more than one answer may be correct. which of the following is a characteristic of unicellular organisms? they can possess tissues and organs. all of their functions are performed by a single cell. they are usually microscopic. each of their cells is specialized to perform a specific function.

Why is permeable soil best for plants that need a lot of drainage?

What are four significant sources of ghgs that come from wostem washington?