Which gas forms 21 percent of earths atmosphere?

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

List 3 factors commonly used to select the location of a city

How are the arctic and antarctic circles alike?