Human use of groundwater has over time.
a. increased
b. decreased
c. decreased and then increased
d. remained the same

The correct answer is a. increased. This is because we've developed techniques to make it more and more useful and groundwaters now supply for more than 90% of water used in rural areas. They are also commonly used for irrigation and have been for millennia. It can easily be extracted thanks to modern technology.

The answer is the magnetosphere.

The us is first  the  u.s. economy  remains the  largest in the world  in terms of nominal  gdp. however, the  u.s. economy  loses its spot as the number one  economy  to china when  measured  in terms of  gdp  based on ppp. in these terms, china's  gdp  is $23.19 trillion exceeds the  u.s. gdp  of $19.42 trillion