A、Alcohol use. B、Childhood abuse. C、Unsafe driving. D、Bad eating habit. A短文最后指出，酒精饮用是世界第三大致病因素，仅位于儿童营养不良和不安全性行为之后，故答案为A)。

Drinking alcohol is socially acceptable behavior in many parts of the world. Some medical experts say light drinking may be good for your health, especially for the heart. But they say these health benefits should be compared to the many health risks linked to alcohol use. The use of alcohol dates back more than 10,000 years. From then until now, alcohol has played an important part in human civilization.(16)It is used in cultural and religious ceremonies, at social gatherings, and even for medical purposes. Alcohol affects every organ in the body.(17)When alcohol enters the body, some of it goes immediately to the stomach and the bloodstream. Once alcohol enters the blood, it is pumped throughout the body by the heart.
    There has been a large amount of research done on alcohol and its effects on human health. Much of the research has examined the harmful effects.(18)But, some research suggests that having one to two drinks of alcohol a day may offer some health benefits. Several large studies have shown that this type of moderate drinking may lower the risk of heart disease, stroke and diabetes. Moderate drinking has also been linked to a reduced risk of death from heart attack.
    On the other hand, the World Health Organization says the harmful use of alcohol results in 2,500,000 deaths each year. This number includes more than 300,000 people between the ages of 15 and 29.(19)The WHO says alcohol use is the world’s third leading cause of disease, after childhood malnourishment and unsafe sex.
16. What role has alcohol played in human history?
17. What happens when alcohol enters the body?
18. What is considered as moderate drinking that can offer health benefits?
19. Which of the following is among the top three leading causes of disease?