middle- and old-age

• 中老年

middle- and old-age的用法和样例：

例句

1. This system can be used to the high contagious disease and old patients.
   该系统特别适用于高传染性疾病的治疗与中老年患者。
2. 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.
   中老年妇女血清雌激素水平与冠心病心功能相关性及运动试验诊断价值的研究。