UE4-The meshes material not showing

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		  			 			[FONT=&amp][size=13]Hello,im new in the UE4,and i downloaded a assets pack,to start making my own landscape,i copy pasted the assets files from rar. to my UE4 project folder,and now when i launch Unreal Engine and try to place a tree or something else in the meshes folder,the object don't have color As you can see in this picture:

[FONT=“Helvetica Neue”][size=13]So,can someone help me??I’m new in the UE4,so i want a detailed explanation,how can i add a material to this tree? [/size]