What do we call visible light? We call it color. But the colors are only the names we give to the way light behaves when it hits something.
"Nothing is too high for a man to reach, but he must climb with care and confidence."
经济周期并不像曾经认为的那样仅仅是围绕稳定趋势的波动,而是反映了经济中更深层次的结构性变化。
在竞争激烈的市场中保持领先的关键是创新。