Many people imagine that Alzheimer's disease (早老性痴呆病), the degenerative disorder that ultimately leaves sufferers with total memory loss, is an inevitable result of aging.This is not so.【C1】______ the risks of contracting the disease increase with age, there are many elderly people【C2】______ memories are perfect.Most of us are so ill-【C3】______ about all forms of memory loss that we label everything as 'Alzheimer's'.Alzheimer's disease itself can【C4】______ people as young as 30 and can progress either quickly or slowly.It can also【C5】______ the blame for other non-degenerative conditions such as deep depression.【C6】______ , only an examination of the brain tissue during an autopsy (解剖) can produce an accurate【C7】______ of the disease.
The causes of Alzheimer's are unknown.They may be either【C8】______ or environmental.A study in 1996 of 13,000 people whose parents or siblings had the disease showed they had five times【C9】______ chance of succumbing 【C10】______ the age of 80 than those with no family【C11】______ of the problem.
There are other factors, however.In a study of identical twins, it was found that only about half of the twin pairs developed Alzheimer's and, when both twins【C12】______ .it, they did so as【C13】______ as 15 years apart.The possibility【C14】______ environment plays a part was【C15】______ by another 1996 study, this time of two groups of elderly Japanese men.One group lived in Hawaii, the other in Japan.The Hawaiian group had a much higher【C16】______ of the disease.
Aluminum has been blamed for the development of Alzheimer's.This is because a high level of aluminum has been found in the brains of sufferers.The disease was first diagnosed at the beginning of the 20th century.It was at this time【C17】______ aluminum was becoming widely available for use in cooking pots.
Memory loss, difficulty in【C18】______ familiar tasks, and problems with abstract thinking are all【C19】______ of the onset of the disease.One unusual feature is its impact on language.It attacks nouns first,【C20】______ verbs.Grammar is one of the last things to go.
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