For the first question, the age of each strip of rock is needed to determine the rate of seafloor spreading. The answer is B.
For the second question, the answer is A.
Chemical changes occur when bonds are broken and/or formed between molecules or atoms. This means that one substance with a certain set of properties (such as melting point, color, taste, etc) is turned into a different substance with different properties. ... One good example of a chemical change is burning a candle.
(Sorry if this didn’t help)
Explanation:
When oceanic crust converges with continental crust, the denser oceanic plate plunges beneath the continental plate. This process, called subduction, occurs at the oceanic trenches. The entire region is known as a subduction zone. Subduction zones have a lot of intense earthquakes and volcanic eruptions.
That they were known for their remarkable ability to change body color and pattering.