But at age twelve he changed to guitar and never looked back.

VOA: special.2010.03.12

Of course the price of gold never changed in the gold standard because that was the whole point of the gold standard that's if currency was convertible into gold.

当然，在金本位制度中,金子的价格从来没有变过,因为这是金本位制度,的核心所在,如果货币能够与金子转换的话。

耶鲁公开课 - 金融市场课程节选

Now, if that potential changed and it stayed changed forever, then the cell would never go back to its resting state.

如果电势变化并且不再恢复到原始电势,细胞就永远不会回到静息状态

耶鲁公开课 - 生物医学工程探索课程节选