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  3. Two recent studies have confirmed the belief that size does matter, at least when it comes to cancer. The first builds on previo

Two recent studies have confirmed the belief that size does matter, at least when it comes to cancer. The first builds on previo

admin2013-08-22  68
问题     Two recent studies have confirmed the belief that size does matter, at least when it comes to cancer. The first builds on previous evidence that being overweight is a major risk factor for breast cancer, and the second suggests that tall people are prone to a number of common cancers.
    Our bodies contain trillions of cells that are constantly renewing or repairing themselves. Normal cells know where they are in the body, and behave appropriately. They grow and reproduce only when required, and self-destruct when they come to the end of their life. But, because of the problems in their software(DNA), cancer cells no longer respond to these normal signals and grow out of control.
    Numerous mistakes are made during cell division every minute of every day and the body has natural defense systems to spot the damage and repair it, or kill the affected cells. The more cells you have, and the longer you live, the greater the odds of one of these mistakes slipping through. And that is without the external influence of carcinogens(诱癌因素).
    Risk factors such as being overweight or taller than average are not direct carcinogens and it is often unclear why they increase the risk of cancer. The link with height may simply be down to taller people having more cells, meaning that there is more opportunity for things to go wrong. The link with obesity is likely to be more complex, but in the case of breast cancer it is thought that overweight women tend to produce more oestrogen(雌激素), a hormone(荷尔蒙)that can act as a "fertilizer" for some types of breast cancer.
    Whatever the cause, the result is the same. Once enough mistakes have occurred for a cell to escape the body’s normal control mechanisms, it divides unchecked and a tumor(肿瘤)develops.
    Will we have a cure? Probably not. But recent advances using drugs that target proteins in cancer cells to control their growth and spread suggest that we are about to enter an era when we may be able to slow and control cancer to such an extent that it will become a chronic(慢性的)disease that can be held in check.
What will happen if too much mistakes enable a cell to escape the control of the body?
选项 A、The cell will destroy itself.
B、The body will lose more cells.
C、The body will still be healthy and normal.
D、The cell will divide improperly to form a tumor.
答案D
解析 根据题干关键词mistakes，a cell，control定位到第五段第二句：Once enough mistakes have occurredfor a cell to escape the body’s normal control mechanisms，it divides unchecked and a tumor develop．一旦错误足够多，细胞能逃离身体正常控制机制时，它就会未经检验而分裂，致使肿瘤形成。故D)项符合表述。B)项是原文的合理推断，故为答案。
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