Which resource is a renewable resource?
coal
gemstones
metal
trees

Trees

Explanation:

As trees can be grown again.

trees

Explanation:

A renewable resource is one that you can extract and it will replenish (grow) back in a short amount of time (think a human generation or two, a range similar to 25-50 years).

Trees will regrow within that time if the land is left unused and there are still the proper conditions to grow.

Coal, gemstones and metal form over a period that is counted more like thousands of years, so you cannot simply return later to the same spot to find more, especially since they need specific conditions to form, and those conditions (like pressure) will not be there anymore.

the reason is because the moon has some form of gravity, and that gravity pulls the ocean tides.