The price of every thing rises and falls from time to time and place to place; and with every such change the purchasing power of money changes so far as that thing goes.
每一种东西的价格都会因时间和地点的不同而涨落；每一次这样的变化都会改变货币的购买力。
The coal industry must evolve or risk becoming obsolete. Adaptation is the key to survival.
孩子不能从环境中得到回应，与外界互动的机会就会遭受剥夺。