Why was the concern over global cooling replaced with a concern over global warming?
a. the science community needed a cause to frighten the general population.
b. steady surface temperature increases were noted between the 1970’s and 90’s.
c. air pollution only became a concern in the 1980’s.
d. scientists observed severe ocean acidification.

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!

If scientists only detect p waves in a certain layer of earths interior what does that tell us?

Plzz on what physical process is responsible for the creation of volcanoes, earthquakes and ocean trenches at the plate margins?