Answer:
area of land dropping steeply towards deep ocean basins
Hi!
Our sky is blue because air molecules will span out <em>blue </em>light from our sun more than <em>red </em>light from our sun.
If you look at the sun, you'll see orange and red colours due to the fact that the suns blue light has already been disbursed away from our line of sight.
Hopefully, this helps! =)