会有热情减退的时候么？Were there occasions when enthusiasm ebbed?眼球晶状体的柔韧性随着年龄增长而减退。The flexibility of the lens decreases with age.记忆力减退是与老年相伴出现的.Loss of memory is a natural concomitant of old age....
Astronomers have discovered a distant galaxy.天文学家们发现了一个遥远的星系。The Galaxy consists of 100 billion stars.银河系由1,000亿颗恒星组成。The spaceman flew through the galaxy at the speed of light.太空人以光速穿越银河系.We report Chandra observations ...