[单项选择]

The fitness movement that began in the late 1960s and early 1970s centered around aerobic exercise. Millions of individuals became (1) in a variety of aerobic activities, and (2) thousands of health spas (3) around the country to capitalize on this (4) interest in fitness, particularly aerobic dancing for females. A number of fitness spas existed (5) to this aerobic fitness movement, even a national chain with spas in most major cities. However, their (6) was not on aerobics, (7) on weight-training programs designed to develop muscular mass, (8) , and endurance in their primarily male (9) . These fitness spas did not seem to benefit (10) from the aerobic fitness movement to better health, since medical opinion suggested that weight-training programs (11) few, if (12) , health benefits. In recent years, however, weight training has again become increasingly (13) for ma
A. emerging
B. hovering
C. intriguing
D. mingling