Match each method of erosion with the correct definition. 1. transport of large boulders along the bottom of a riverbed saltation 2. rocks carried by the river smash together and break into smaller pieces abrasion 3. rocks smash into the river bed and banks and break into smaller pieces traction 4. weak acids in the water dissolve the minerals in rock attrition 5. sediment is lifted off the ground and carried by wind over a short distance solution

1. Traction - transport of large boulders along the bottom of a riverbed  
It is a type of transportation that occurs in rivers where larger rocks roll and slide along the riverbed. 

2. Attrition - rocks carried by the river smash together and break into smaller pieces 

This is a method of erosion where the rocks that are being carried by the river bash against each other and break, reducing in size as a result. 

3. Abrasion - rocks smash into the river bed and banks and break into smaller pieces. 

This method of erosion occurs when rocks or particles that are already being transported ram into the beds and banks of the river.
 
4. Solution - weak acids in the water dissolve the minerals in rock attrition.

This occurs mostly in carbonate rocks like limestone. They are broken down by the weak acids and dissolved. The solution is then carried away by the river.  

5. Saltation - sediment is lifted off the ground and carried by wind over a short distance.

This is a transportation process where the particles are small enough to be lifted from the bottom of the river but is still to heavy to be suspended. As a result it bounces along the riverbed.