Think about the importance of energy. Without a source of energy organisms cannot respond, build, reproduce, or carry out most of the functions of living things. From where does our energy come? Explain how Photosynthesis and Cellular Respiration are important in your everyday life. Be Scientific! 5-6 sentences!

one of the most common forms of pain or discomfort we feel during strenuous exercise is a burning sensation in our lungs or muscles that goes away shortly after we cease the activity. this is caused by a build-up of lactic acid.

the answer is a or when it says crossing over

answer; both surfaces of the membrane are nonpermeable