Before the development of isotopic dating methods, scientists estimated the age of the Earth by: a. estimating eruption rates of volcanoes.
b. comparing rates of change on the Earth's surface today with the geologic record.
c. counting tree rings.
d. determining the time it takes to create fossils like shark teeth.

There are 4 red balls, 6 white balls, and 3 green balls in a bag. if one ball is drawn from the bag at random, what is the probability that it is not white?

Look at the data above. provide an explanation for europe’s projected population decrease by the year 2050. (i'm doing this for future kids) the answer is : the percentage of people over the age of 65 and under the age of 15 in europe is currently the same at 16% each. therefore, the majority of the population is between the ages of 16 and 64. in forty years from now, in 2050, a greater percentage of the population will be over the age of 65. europe also has a relatively long life expectancy of 75 years. this, combined with a low birth rate means that by 2050 europe’s population will actually be less than it is today.

Which of these is a drawback of using natural gas? a. it is fairly safe for use in homes. b. it burns more cleanly than crude oil products. c. scientists have developed new ways of extracting it. d. during its extraction, groundwater can be contaminated.