COLUMNA
1. also called spreading centers.
2. Years it will take for cooling tocomplete.
3. rift valley
4. longest topographic feature.
5. average spreading rate
6. location of fast spreading rate
. 7. 4,000 kilometers in miles.
8. oceanic ridge represent how many % of the Earth's surface?
9. resemblance of the ocean basin.
10. 70,000 kilometers in miles.

COLUMN B
A.80 million years
B.30%
C.2,500miles
D.oceanic ridge
E.baseball seam
F.2cm per yr.
G.Divergent boundary
H.east pacific rise
J.20%
K.deep down faulted structure​