During that period, most of the world's big landmasses were connected in what scientists call Pangea.

在此期间，世界上大部分大片陆地都连接在科学家所谓的盘古大陆上。

They could be rocky like Earth or water worlds without landmasses.

它们可能跟地球一样多岩石，也可能是没有陆地的水世界。

The larger the landmass, the less of impact these change have.

地域越广，这种变化的影响越小。

Historians estimated the empire once ruled more than 400 million people and had 25 percent of the earth's landmass.

历史学家估计，这个帝国曾经统治着超过4亿人口，拥有地球25%的陆地。

It's believed the emergence of landmass began roughly 4 billion years ago.

也就是陆地上升时期大约始于40亿年前。

Eventually, the landmass will break right off, giving birth to a brand new ocean.

最终，这片地块会分裂，孕育出一片崭新的海洋。

The life that was hit the hardest was that lived on the smaller landmasses.

受到最大打击的生命是生活在较小陆块之上的那些。

An ice shelf is a large floating sheet of ice permanently attached to a landmass.

冰架是永久附着在陆地上的一块巨大的漂浮冰层。

Roughly 70% of Earth's surface is water, and much of its landmass is unpopulated.

因为大约70%的地球表面都是水，而即便是陆地，也还是有很多地方是无人居住的。

Trees and vegetation currently cover over 50% of Singapore's landmass, reducing the need for air conditioning and encouraging low-pollution transportation.

目前，树木和植被覆盖了新加坡 50％ 以上的陆地，减少了对空调的需求，并鼓励了低污染的交通运输方式。