Acalcium-rich nonfoliated rock that is often associated with economically valuable mineral deposits is
a. skarn
b. marble
c. phyllite
d. quartzite

which type of foliated metamorphic rock is an intermediate between slate and schist?
a. skarn
b. gneiss
c. phyllite
d. quartzite

The answer to the first question is B (marble).

Marble is a non- foliated  metamorphic rock that forms when limestone is subjected to the heat and pressure of metamorphism. it is  composed primarily of calcium carbonate and usually contains other minerals such as clay minerals, mica, quartz, iron oxide and graphite.

The answer to the second question is C (phyllite).

Phyllite has a texture that is intermediate between slate and schist. This results in slaty cleavage and shiny cleavage surfaces but grains that are still microscopic.

the leaf is an organ of a typical plant, and the main functions are to complete photosynthesis and allow the plant to exchange gas, just like how we have the respiratory system. leaves have the stomata, which collects maintains co2 and o2 levels. this is necessary for cell metabolism. the leaf also collects sunlight using chloroplasts. succinctly, leaves own a pivotal role in sustaining plant life.