问题
选择题
| 下列关于作用力与反作用力，下列说法正确的是（ ） |
| A．一对作用力和反作用力的合力为零 B．某物体若只受一个力的作用，说明可以只有作用力，而没有反作用力 C．大小相等、方向相反、作用在同一物体上的两个力必定是一对作用力和反作用力 D．一对作用力和反作用力性质相同，总是同时产生、同时变化、同时消失 |
答案
答案：D
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| 下列关于作用力与反作用力，下列说法正确的是（ ） |
| A．一对作用力和反作用力的合力为零 B．某物体若只受一个力的作用，说明可以只有作用力，而没有反作用力 C．大小相等、方向相反、作用在同一物体上的两个力必定是一对作用力和反作用力 D．一对作用力和反作用力性质相同，总是同时产生、同时变化、同时消失 |
答案：D
Passage Three
| Health-care services will account for almost one-fifth of all job growth during the 1996～2005 period. Home health-care aids will assist the elderly, disabled, and seriously ill in the patient’s home instead of a health facility. A large number of openings for this field is expected due to very rapid growth and high turnover. In fact, home health-care aids are expected to more than double in number by the end of 2005. Part of the reason for this increase is the growing population of elderly people. The number of people in their 70s and older is projected to rise substantially. This age group is characterized by mounting health problems that require assistance. There will also be an increasing reliance on home care for patients of all ages. This trend reflects several developments: Efforts to contain (抑制，控制) costs by moving patients out of hospitals and nursing facilities as quickly as possible; the realization that treatment can be more effective in familiar surroundings; and the development of portable medical equipment for in-home treatment. Turnover in this field is high, which is a reflection of the relatively low skill requirements, low pay, and high emotional demands of the work. Therefore, people who are interested in this work and properly suited for it should have excellent job opportunities, particularly those with previous experience. Physical therapy, too, is predicted to increase rapidly through 2005. A growing population of elderly people, who are vulnerable to chronic and debilitating (虚弱的) conditions, means that more therapeutic services will be needed. More young people will also need physical therapy as medical advances save the lives of a larger proportion of newborns with severe birth defects. Growth will also result from advances in medical technology that permit the treatment of more disabling conditions. In the past, for example, the development of hip and knee replacements for those with arthritis gave rise to employment for physical therapists to improve flexibility and strengthen weak muscles. The growing interest in health promotion should also increase the demand for physical therapy services. More employers are now evaluating work sites, developing exercise programs, and teaching safe work habits to employees in the hope of reducing injuries. A shortage of physical therapists that once existed has all but disappeared. The number of physical-therapy education programs has increased, and more graduates have moved into the labor force. Most graduates receive multiple job offers, and job prospects are expected to continue to be excellent. Physical therapists who are willing to work in rural areas will experience even better opportunities. |
Graduate from physical-therapy education programs ______ .
A．have difficulties in finding jobs
B．aren’t willing to work in rural areas
C．aren’t willing to stay in this profession
D．have good job opportunities