Identify the structure of the human heart which is valve between the left atrium and left ventricle of the heart, consisting of two triangular flaps of tissue that prevents blood from flowing back into the atrium. also, called the bicuspid valve.

bacteria could be both, harmful and to us. harmful bacteria could make us sick and probably even by getting the chances of getting a disease, but good bacteria fight it off with your immune system. there is always bacteria everywhere we go. we need to make sure to wash our hands after using the restroom, before eating, after eating, after petting an animal too. so you see, bacteria is everywhere and is harmful or . i hope this . : ) : ) : )