impermanent

The sandcastle is a beautiful but impermanent structure that the tide will soon wash away.

(Chinese) 沙堡是一座美丽但非永久的建筑，潮水很快就会把它冲走。

In many Eastern philosophies, the physical world is seen as impermanent and constantly changing.

(Chinese) 在许多东方哲学中，物质世界被视为是虚幻无常且不断变化的。