Metals are extracted from their ores.
many copper ores contain only 2% of copper compounds.
copper is now extracted from ores containing a low percentage of copper compounds.
suggest two reasons why.

Smog is the term used to describe the combination of fog and smoke

In salt water solution,the salt is the blank

An animal cell loses the ability to convert energy stored in food to energy that the cell can use. which of the cell's organelles has stopped working? a.the mitochondria b.the nucleus c.the vacuoles d.the endoplasmic reticulum