what is amethyst? bc i have an amethyst crystal, my aunt says it helps with bad dreams and stress but how does it help, i also have green quartz, clear quartz and rose quartz

Northeastern china, north korea, northern japan containing coniferous forests, temperate grasslands, and agriculture, are all part of what climate zone? a. tropical desertb. desertc. humid subtropicald. humid continental

What is the amount of organic matter in all living organisms in a habitat called?

How can studying economics us make better choices about how to use scare resources