Which of these best describes erosion?

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

2pi more meters because you find the circumference which is 6pi and 4pi and subtract it and you get 2pi

No, because you are more likely to see volcanic mountains where magma is rising along the mid-ocean ridge spreading to the center.

I'm going to say it's 5-6 million