The purpose of the mucus found within the respiratory system is to a. trap particles from the air before they reach the lungs. b. lubricate the epiglottis. c. push the cilia away from the lungs. d. move air through the windpipe.

Which statement describes characteristics of planarians? a they live in oceans, are parasites, and reproduce only sexually. b they live in fresh water, are parasites, and reproduce only asexually. c they live in oceans, are free living, and reproduce sexually and asexually. d they live in fresh water, are free living, and reproduce sexually and asexually.

Drag each description to the correct location on the image. not all descriptions will be used. describe the parts of a comet. the frozen part of the comet the atmosphere of gases and dust formed when the nucleus vaporizes tail made of small, solid dust particles tail made of ions that appears to point away from the comet's orbit

What organ is the first to receive nutrients that have been absorbed from the digestive tract?