On the other hand sociability delivers a manifold and inexhaustible source for his studies in order to satisfy his natural urge.

其二，交际为人类提供了丰富无尽的探索资源，从而这股自然冲动也得到了满足。

It is the people who are the inexhaustible source of power that drives development.

发展的不竭力量蕴藏在人民群众之中。

Solar energy has the obvious advantage that the sun is an inexhaustible and abundant source which is free of both pollution and radioactivity.

由于太阳是没有污染和放射性的无穷无尽的丰富资源，具有明显的优点。

Solar energy is lauded as an inexhaustible fuel source that is pollution and often noise free. The technology is also versatile.

太阳能被称为是取之不尽的能源，没有污染，通常也没有噪声，而且用途广泛。