its C because i just anwserd it & it was right
Answer:
Convergent.
Explanation:
Just as oceanic crust is formed at mid-ocean ridges, it is destroyed in subduction zones. Subduction is the important geologic process in which a tectonic plate made of dense lithospheric material melts or falls below a plate made of less-dense lithosphere at a convergent plate boundary.
Explanation :
Absorption coefficient of a material determines how much sound is absorbed by the material.
To build a soundproof room, Heavy curtains and carpet can be used. They reduce reverberation.
Reverberation means an echoing sound which persists for some time. For example, when we bang on a huge piece of metal, we hear the reverberation even after we stop banging.
Hence, option (A) and (D) are correct.
Answer: B
It can exist in many alloys, usually with a carbon base
Explanation:
Iron forms many alloys with a carbon base. Steel is an alloy of iron and carbon. There are many different types of steel needed for different applications. Various metals are added to tune the steel to the required properties. For instance, stainless steel contains 10-30% chromium in addition to iron and a low percentage of carbon. Steel remains an extremely versatile alloy used for many different purposes.