If two pieces of ocean crust meet at a convergent boundary, which piece tends to curl under and back into the mantle Older crust
Or
Younger crust

Match the vocabulary word with its meaning

[fw.02]sinkholes are often formed as a result of the actions of. a.heat on recharge b.pressure on aquifers c.acid in groundwater d.minerals in hot springs

From the standpoint of geography,a is an internal rendering of an individual's known world