but it's just a drop in the ocean compared to that at the southern end of our planet.但和南极比起来就只是沧海一粟了

compare to:和...比较

Can you tell me how this compare to that?

你能告诉我这个和那个比较起来如何？

Compare to other vehicle, car is really quite convenient.

同其他车辆相比，汽车确实很方便。

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

by far:到目前为止

This is by far the largest cake in the world.

这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.沙克尔顿和他的两名同伴划了艘小船出去寻求援助

set off:出发

What time are you planning to set off tomorrow?

你打算明天几点钟启程?