1 : Canadian Shield - tundra. 
This means that it's characterized by low temperatures which stop and limit plant growth. It's similar to the desert, except it has more precipitation
 2 : Alaskan plains - subarctic
Due to its closeness to the arctic. 
3 : Seattle, Washington - Marine west coast (West Coast of the Pacific Ocean - the closeness of the ocean has a determining influence on the climate)
 4 : Washington, D.C. humid continental climate, with mild but wet winters