Limestone tends to form natural caves to which of the following?

a. its tubular structureb. its sedimentary naturec. its chemical compositiond. its porous and nonporous layers

What is the primary justification of the hypothesis that the early earth environment was void of oxygen? ( 2 points) data showing the concentrations of gases extracted from rocks fossil evidence regarding the origin of eukaryotes generally accepted atmospheric conditions molecular evidence based on evolutionary traits.

The earth's internal process which drives seafloor spreading is

Why have the countries of the region had difficulty establishing democratic governments in recent years? choose all answers that are correct b is also correct i need to know if theres any morecommunists have overtaken the countries of the caucasus region. the soviets established national borders in the region without considering the location of ethnic groups. fighting continues between armenia and azerbaijan over the nagorno-karabakh region. civil war between communists and islamic groups in tajikistan resulted in thousands of deaths and refugees are forced to flee. in a test!