One reason performance declines on sultry, humid days is that working muscles have to compete with the skin for blood.

在闷热潮湿的天气里运动能力下降的一个原因是，运动中的肌肉必须与皮肤争夺血液。

Hearing normally declines as people age.

听力通常随着年龄的增长而减弱。

When grandmama urges her, she always declines politely.

奶奶催她时，她总是婉言谢绝。

Their big feet might be hurting the largest member of the weasel family as snowpack declines across much of North America.

当北美许多地区积雪消融的时候，它们的大脚掌也许会伤害到那些黄鼠狼家族中最大的成员。

While the rate of growth in the use of energy declines as an economy matures, no country has yet reduced energy use while raising gross domestic product.

虽然能源消耗的低增长是经济体系成熟的表现，还没有国家能做到在提高国内生产总值的同时减少能源的使用。