Earth is the only known planet to have oceans of liquid water.
The question seems poorly worded, but Earth is the planet with liquid water on its surface.
earth is the only KNOWN planet with liquid H2O
Earth..?
Earth
Earth, because it is the only planet with liquid water.
It's the Earth.
earth is the only planet where the same substance can exist in gaseous , liquid , and solid form
Ours - Earth.
Earth is the only known planet with liquid water.
Earth is the only planet known to have life and liquid water.
Only earth.