Section B
Directions: There are 2 passages in this section．Each passage is followed by some questions or unfinished statements．For each of them there are four choices marked A, B, C and D．You should decide on the best choice.
An exercise program designed for younger s may be inappropriate for older persons, particularly for persons over age 50．Special attention must be paid to matching the program to the interests and abilities of the participants．The goals of the program should include both social interaction and physical conditioning.
Older s should take a physical examination before starting a fitness program．Included in this examination should be a stress cardiogram(心电图) , blood pressure check, and an evaluation of joint functioning．It is a good idea for participants to learn how to monitor their own cardiorespiratory(心肺的) status during exercise.
Well-designed fitness programs for older s will have activities that begin slowly, are monitored frequently, and are geared to the enjoyment of the participants．The professional staff coordinating the program should be familiar with the signs of distress．Periods of warm-up and cool-down should be included．Activities to increase flexibility are beneficial in the beginning and ending parts of the program．Participants should wear comfortable clothing, appropriate shoes, and be mentally prepared to enjoy the activities to the fullest.
A program designed for older s will largely conform．to the criteria of activity, intensity, duration, and frequency．The principal exception is in the intensity camp where the THR(Target Heart Rate) should not exceed 120 beats per minute．This level of intensity is approximately 40% to 50% of the maximum heart rate．Also, because of possible joint or muscular or skeletal problems, certain activities may have to be done in a sitting position．Pain and discomfort should be reported immediately to the fitness instructor.
Fortunately, properly screened s will rarely have health emergencies during a well-monitored fitness program．Like their youthful counterparts, many older s find fitness programs socially enjoyable, physically beneficial, and occasionally addictive.
According to the author, ______.