What is the practice of leaving the stocks of crops in the ground to anchor topsoil

Click the item in the left column. use the plus sign to move it up or the minus sign to move it down until it matches the correct entry in the right column. lock your answer in place by clicking the square beside the item. (a checkmark means it is locked.) amazon basin a atacama desert b andes mountains c lake titicaca d peru e patagonia f brazil g chile h suriname

Acontinental polar air mass foms in

Which barrier to economic development is shown in the following examples?