How are the lungs kept free of germs and dirt from the air?

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.

The grooves or folds of the brain are called

|using the periodic tablewarm-upuse the periodic table in the tools bar to answer the following questions.what elemental classification does oxygen belongto? done