How many countries were part of Eastern Europe until 1990

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

If scientists only detect p waves in a certain layer of earths interior what does that tell us?

Which type of seismic waves are confined at the surface