The search for reciprocity laws is a fundamental theme in the history of mathematics.
Love is the only reality, and it is not a mere sentiment. It is the ultimate truth.
她一直是个观察者、倾听者、故事的收集者。
【解释】不孝的事有三件,其中又以没有子孙后代为最大。
你必须能够适应不断变化的市场条件。如果你不能适应,你就无法生存。
The balance between economy and ecology is the core of modern forestry.