Answer: the correct answer is D
Answer: The movement of tectonic plates
Explanation:
Tectonic plates are the part of the earth's crust that both the ocean and land rest on. These plates are constantly moving as a result of currents in the mantle.
These movements cause stress on the surface which has the effect of fracturing rocks and thereby creating/ forming faults in the earth's crust. Sometimes faults form when these plates move away from each other and sometimes they are formed when they push into each other.
Answer: Dampness or moisture introduces hydrogen into the weld, which causes cracking when some metals are welded.
Explanation:
<em>This moisture (hydrogen) is a major cause of weld cracking and porosity. </em>
