Kondratieff waves

例句：

1. 1.The waves of the ocean are constantly changing.
   海洋的波浪不断变换。
2. 2. The waves crashed against the shore.
   波浪撞击着海岸。
3. 3.The waves were so powerful that they lifted the boat up.
   波浪如此强大以至于把船抬起来。