Which extrusive rock forms so quickly that no crystals form?

a) magma

b) pumice

c) lava

d) obsidian

Which continents lie only in the northern hemisphere

Why did the belgian parliament pass laws to decentralize its government? a. to increase trade with neighboring luxembourg b. to decrease the political power enjoyed by the flemish c. to enable belgium to join the european union d. to reduce tensions between belgium's two main ethnic groups

Fossil fuels such as coal, oil, and natural gas were formed over millions of years by