Sustainability is not an option; it's a necessity for the future of mining.

解析：人与天地万物本为一体。

Sometimes we stare so long at a door that is closing that we see too late the one that is open.

我们必须不断地跳下悬崖，并在下落的过程中长出翅膀。

It's on the strength of observation and reflection that one finds a way. So we must dig and delve unceasingly.

最好的建筑是简单的。

好奇心是每一次重大科学进步背后的驱动力。