第三部分:概括大意与完成句子(第23～30题，每题1分，共8分)
阅读下面这篇短文，短文后有2项测试，任务：(1)第23～26题要求从所给的4个选项中为每段选择1个正确的小标题；(2)第27～30题要求从所给的5个选项中选择4个正确选项，分别完成每个句子。

23、回答23-30题：
1Every 45 seconds, someone in America has a stroke. Every 3.1 minutes, someone dies of one.
Stroke killed an estimated 167,661 people in 2000 and is the nation's third leading cause of death, ranking behind diseases of the heart and all forms of cancer. Stroke is a leading cause of serious ,long-term disability in the United States.
2 Stroke is a type of cardiovascular(心血管的) disease. It affects the arteries(动脉) leading to and within the brain. A stroke occurs when a blood vessel that carries oxygen and nutrients(营养物) to the brain is either blocked by a clot(凝块) or bursts. When that happens,part of the brain cannot get the blood(and oxygen)it needs,so it starts to die.
3The brain is an extremely complex organ that controls various body functions. If a stroke occurs and blood flow can't reach the region that controls a particular body function, that part of the body won't work as it should. If the stroke occurs toward the back of the brain, for instance, it's likely that some disability involving vision will result. The effects of a stroke depend primarily on the location of the obstruction(阻塞) and the extent of brain tissue affected.
4The American Stroke Association has identified several factors that increase the risk of stroke.
The more risk factors a persor has,the greater the chance that he or she will have a stroke. Some of these you can't control, such as increasing age, family health history, race, and prior stroke. But you can change or treat other risk factors to lower your risk. Factors resulting from lifestyle or envi-ronment can be modified with a healthcare provider's help. Some of these include : high blood pres-sure,current smoking,heart disease,and high red blood cell count.
5A stroke can happen to anyone at any moment. In fact about 600,000 people have strokes every year. For many years, there was no hope for those suffering a stroke. However, recent break-throughs have led to new treatments. For the treatments to work, the person must get to a hospital immediately.
Paragraph 2 __________.
A．Effects of a stroke
B．Annual cost of stroke in the US
C．Definition and description of a stroke
D．Breakthroughs in treatment
E．Risk factors of stroke
F．Warnin~ signs of a stroke


24、 Paragraph 3 __________.
A．Effects of a stroke
B．Annual cost of stroke in the US
C．Definition and description of a stroke
D．Breakthroughs in treatment
E．Risk factors of stroke
F．Warnin~ signs of a stroke


25、 Paragraph 4 __________.
A．Effects of a stroke
B．Annual cost of stroke in the US
C．Definition and description of a stroke
D．Breakthroughs in treatment
E．Risk factors of stroke
F．Warnin~ signs of a stroke


26、 Paragraph 5 __________.
A．Effects of a stroke
B．Annual cost of stroke in the US
C．Definition and description of a stroke
D．Breakthroughs in treatment
E．Risk factors of stroke
F．Warnin~ signs of a stroke


27、 When a stroke occurs,the arteries leading to and within the brain__________.
A．suffer from a stroke
B．will be affected
C．change their lifestyles
D．will take place
E．occurs at the back of his/her brain
F．controls various body functions


28、 A person's vision is likely to be affected if a stroke__________.
A．suffer from a stroke
B．will be affected
C．change their lifestyles
D．will take place
E．occurs at the back of his/her brain
F．controls various body functions


29、 Some people can reduce their risk of stroke if they__________.
A．suffer from a stroke
B．will be affected
C．change their lifestyles
D．will take place
E．occurs at the back of his/her brain
F．controls various body functions


30、 New treatments are now available to people who__________.
A．suffer from a stroke
B．will be affected
C．change their lifestyles
D．will take place
E．occurs at the back of his/her brain
F．controls various body functions