middle and old aged folks的用法和樣例：
例句
- This system can be used to the high contagious disease and old patients.
該系統特別適用于高傳染性疾病的治療與中老年患者。 - Study on the correlations between serum estrogen level and heart function of coronary heart disease and the evaluation of exercise test in the middle and aged women.
中老年婦女血清雌激素水平與冠心病心功能相關(guān)性及運動(dòng)試驗診斷價(jià)值的研究。
