National variations in PISA scores are more closely tied to educational practices and values at school and at home, not to geography, genes, or immigration. List two countries where this is particularly evident, and explain why you think such variations exist there. (Click the back button to the review the map before answering.)

The correct answer to this open question is the following.

Although the question is incomplete because there is no map attached to answer it, we can say that the top countries in PISA scores are China and Singapore. Educational practices and values at school and at home, not to geography, genes, or immigration represent the reasons why these countries are at the top. This means that the family education system and the public school system of these countries emphasize the children's formation since the family environment and later, in the optimal level of education in their respective school systems.

The PISA system or Program for International Students Assessment is an international examination applied every three to teenagers (15 years-old), evaluating subjects such as science, mathematics, and reading.

c. seafloor spreading occurs.

d. crust becomes molten rock.

e. denser plates slide under lighter plates.