What percent of russians live between the belarus and ukraine borders and the ural mountains?
a. 25 percent
b. 50 percent
c. 75 percent
d. 90 percent

The majority of the Russian population lives between Lithuania, Belarus,  Ukraine borders and the Ural Mountains - for example already 10% to 20% of Russians live in Moscow - so we can reject answers a) and b)

However, i doubt it's 90% - otherwise they wouldn't have built the Transsiberian Railway to Vladivostok - so the correct answer is 75%.

D, the answer is letter d. because even though fossil fuels take a very long time to form, they do form in the ground just like coal and others.