国家本质上是侵略性和扩张主义的，因为它们存在于一个无政府状态的国际体系中，没有更高的权威来约束它们。

解释：大部分蔬菜都偏寒性，而蒜却是温性的，说明了食材性质的差异。

Technological innovation is the core driving force for the high-quality development of the petroleum industry. We must increase R&D investment and break through key core technologies.

The meaning of "knowing" has shifted from being able to remember and repeat information to being able to find and use it.

孩子得到的第一个想法是最重要的。