在当今世界上存在的所有语言中，肯定有已经发展多年的复杂性。

In all the languages existing in the world today, there are complexities that must have been developed for years.

youdao

在当今世界上，快乐可能看起来难以实现。

Happiness might seem tough to achieve in today's world.

youdao

在当今世界上，人们能乘车的时候从来不会走路。

In this modern world of today, people never walk when they can ride.

youdao