but it's just a drop in the ocean compared to that at the southern end of our planet.但和南極比起來就只是滄海一粟了

compare to:和...比較

Can you tell me how this compare to that?

你能告訴我這個和那個比較起來如何？

Compare to other vehicle, car is really quite convenient.

同其他車輛相比，汽車確實很方便。

by far the largest concentration of ice on Earth.是目前地球上冰量最多的地方

by far:到目前為止

This is by far the largest cake in the world.

這是目前世界上最大的蛋糕了。

Shackleton and two companions set off to summon help in a tiny boat.沙克爾頓和他的兩名同伴劃了艘小船出去尋求援助

set off:出發

What time are you planning to set off tomorrow?

你打算明天幾點鐘啟程?