填空题

Carbon monoxide poisoning causes death and injuries throughout the world. The poison gas has been a problem since humans first began burning (36) to cook food or to create heat during cold weather. More people die from carbon monoxide poisoning in the United States each year than from any other kind of poisoning. Carbon monoxide gas is called the such a silent (37) that it is hard for people to (38) it in the air. Yet, carbon monoxide gas is very (39) It steals the body’s ability to use oxygen. Carbon monoxide (40) the ability of the blood to carry oxygen to body tissues. It does this by (41) with the blood. When carbon monoxide links with the blood, the blood is no longer able to carry oxygen to the tissues that need it. (42) to the body can begin very quickly from large (43) of this gas. (44) and the amount of the gas he or she breathes in. Small amounts of carbon monoxide will cause a person’s head to hurt. (45) . The room may appear to be turning around. The person may have trouble thinking clearly. (46) . They will begin to feel very sleepy and very tired. They may have terrible stomach pains.