There is thought to be more than 1,000 billion tons of coal on Earth that can be mined. If 4.5 billion tons are used worldwide every year, for how many years will Earth's coal reserves last?

In the desert, saguaro cacti, owls, horned lizards, and fire ants all share the same space. which of the following can be considered a population? question 9 options: all plants in the same area all cacti in the same area all species in the same area the lizards and the ants