if our air becomes mucky/dirty, then we will get sick from it. if there is manure all over the place, you'd become sick from smelling it for too long. simple. ^^
so, the answer is d. :D
1. fault block mountains develop in areas where widespread uplift causes fragmentation of the upper crust, also have steep dips
2. major mountain belts formed by volcanism intrusion and horizontal shortening
:D
It is a rational statement
Oceanic crust is more dense which makes it subduct and continental crust is less dense which makes it override the oceanic crust during subduction
