It is clear that some people who participate in exercise training will develop injuries to their bones, muscles, and joints (关节). Despite unfounded reports in the mass media of extremely high injury rates among adult exercisers, there have been few good studies of exercise injuries in populations. One of the difficulties in performing such studies has been the need to identify both the number of cases and the number of people at risk for injury. In other words, it is difficult to know the number of individuals injured and the total number of individuals exercising in the population. But these two figures are necessary in order to calculate (统计) tree injury rates. Normally, injury is defined as an accident that causes a person to stop exercising for at least one week. The best available studies on injury rates show that about 25 to 30 percent of adult runners become "injured" (based on the above definition) over the course of a year. More serious injuries include those for which the injured person seeks medical care. If only they are considered, injury rates are much lower, perhaps in the range of I percent per year.
Little is known about the causes of exercise injuries. One factor that has been linked to injury is the amount of exercise; for example, individuals who run more miles are likelier to be injured than those who run fewer miles. Factors such as age, sex, body type, and experience have not been shown to be associated with risk of injury. It seems logical that structural abnormalities, sudden increases in training intensity, and types of equipment used are likely to be related to injury risk. However, data to support these opinions are not available.
The true injury rates are obtained from（）
A．the average number of injuries for each individual
B．the amount of exercises for each individual
C．the numbers of the injured and all individuals in training
D．the numbers of people doing exercises and those stopped exercises for one week
参考答案：C
解析：
事实细节题。本题询问的是真实的受伤率是如何获得的。根据文章第一段第二句、第四句和第五句可知，掌握受伤者的数量和进行锻炼者的总数对于计算真实的受伤率是必要的。因此，选项C(受伤的人数和所有进行锻炼的人数)符合文意，为正确答案。
[避错指南] 选项A(每名锻炼者平均的受伤量)与选项B(每名锻炼者的锻炼量)均没有在文章中提及，可以先排除。选项D(进行锻炼的人数和停止锻炼至少一个星期的人数)比较具有迷惑性。虽然文中出现“一般说来，导致人们停止锻炼至少一星期的意外事故，被称为损伤”，但是除此以外，还有比这更为严重的受伤，一星期不能进行锻炼只是损伤的一种情况，用此数据来进行统计则过于片画，因此可予以排除。