Answer:
Oceanic crust and continental crust
Explanation:
A subduction zone is normally between oceanic crust which is made of basalt and continental crust which is made of granite. Oceanic crust is denser than continental crust. So when oceanic crust collides with continental crusts, it subsducts underneath the continental crust since it is denser.
As it is given that Bulk modulus and density related to velocity of sound

by rearranging the equation we can say

now we need to find the SI unit of Bulk modulus here
we can find it by plug in the units of density and speed here

so SI unit will be

SO above is the SI unit of bulk Modulus
Transmission of information in ANY form can be done digitally
or analoguely.
Beginning about 30 years ago, everything slowly started changing
to digital. Today, all commercial satellite communication, all optical
fiber communication, all internet communication, all computer
communication, all commercial cable communication, all commercial
television, and much of the telephone system, are all digital.
On your computer ... .pdf, .jpg, .mp3 etc. are all digital methods of
moving and storing information.
AM and FM radio are an interesting subject. They're all still analog.
They could easily be changed to all digital, and it would be a big
improvement, both for the broadcasters and for the listeners.
BUT ... every AM and FM radio that anybody has now would be
obsolete. Every single radio would either need to be replaced,
OR you'd need to add a digital decoder to every radio, like we
had to do with our TV sets a few years ago when television
suddenly became all digital. With AM and FM radios, the decoders
would be bigger, and would cost more, than most of the radios.
And that's why commercial radio broadcasting is still analog.
602.496 J I think, I hope this helps!