Which is a serious problem associated with landfills?

attracting rodents
admitting toxic fumes
running out of space
causing cancer

The primary function of the respiratory system is to supply the blood with oxygen in order for the blood to deliver oxygen to all parts of the body. the respiratory system does this through breathing. when we breathe, we inhale oxygen and exhale carbon dioxide. this exchange of gases is the respiratory system's means of getting oxygen to the blood. respiration is achieved through the mouth, nose, trachea, lungs, and diaphragm. oxygen enters the respiratory system through the mouth and the nose. the oxygen then passes through the larynx (where speech sounds are produced) and the trachea which is a tube that enters the chest cavity. in the chest cavity, the trachea splits into two smaller tubes called the bronchi. each bronchus then divides again forming the bronchial tubes. the bronchial tubes lead directly into the lungs where they divide into many smaller tubes which connect to tiny sacs called alveoli. the average adult's lungs contain about 600 million of these spongy, air-filled sacs that are surrounded by capillaries. the inhaled oxygen passes into the alveoli and then diffuses through the capillaries into the arterial blood. meanwhile, the waste-rich blood from the veins releases its carbon dioxide into the alveoli. the carbon dioxide follows the same path out of the lungs when you exhale. the diaphragm's job is to pump the carbon dioxide out of the lungs and pull the oxygen into the lungs. the diaphragm is a sheet of muscles that lies across the bottom of the chest cavity. as the diaphragm contracts and relaxes, breathing takes place. when the diaphragm contracts, oxygen is pulled into the lungs. when the diaphragm relaxes, carbon dioxide is pumped out of the lungs. write one paragraph (at least 6 sentences) describing the path of oxygen through the respiratory system. also include why this "order of operations" is the way it is!

Which of these is likely to be the best source of valid health information?

From the list below, choose all the correct statements about the functions of fat. select all that apply. select all that apply. fat provides flavor and texture to food (think ice cream) and also leaves you satisfied for longer after a meal. fat in the diet allows for the transport of vitamins a, c, and e because they are fat-soluble. lipids are an essential component of cell membranes, act as insulation under the skin, and protect organs from injury. the body can rely on carbohydrate stores during periods of low energy intake. fat is a good source of energy providing 4 kcal/g.