Carbon monoxide poisoning causes death and injuries throughout the world. The poison gas has been a problem since humans first b

admin2013-06-17  21

问题     Carbon monoxide poisoning causes death and injuries throughout the world. The poison gas has been a problem since humans first began burning【B1】______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【B2】______that it is hard for people to【B3】______it in the air. Yet, carbon monoxide gas is very【B4】______It steals the body’s ability to use oxygen. Carbon monoxide【B5】______the ability of the blood to carry oxygen to body tissues. It does this by【B6】______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.【B7】______to the body can begin very quickly from large【B8】______of this gas.【B9】______and the amount of the gas he or she breathes in. Small amounts of carbon monoxide will cause a person’s head to hurt.【B10】______. The room may appear to be turning around. The person may have trouble thinking clearly.【B11】______. They will begin to feel very sleepy and very tired. They may have terrible stomach pains.
【B3】

选项

答案realize

解析 由不定式确定,此处缺少一个动词的原形,it为形式主语,不定式与该动词短语为真正的主语。
转载请注明原文地址:https://kaotiyun.com/show/y8M7777K
0

最新回复(0)