这是因为地球的三分之二是由浩瀚的海洋组成的。
This is because two thirds of the earth is made up of vast oceans.
从地球上看，NGC 6744的大小差不多等于三分之二个满月。 可惜的是，由于太过昏暗，我们惟有通过后院式望远镜才能观测到它。
Viewed from Earth, NGC 6744 is about two-thirds the size of a full moon, but it's so faint you can't see it without a backyard telescope.
系统而详实了解覆盖地球表面三分之二的海洋水域的化学特性、地形及水流特性代价高昂，但是可以实现的。
Systematic and detailed understanding of the chemistry, topography and flow of the waters that cover two-thirds of the planet would be costly, but it could be achieved.
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