أرسل هذا في رسالة قصيرة: Soil fertility affected by land use history, relief position, and parent material under a tropical climate in NW-Vietnam

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 / ____||   / _ \\  | || | ||  |  ___||   ____    
/ //---`'  | / \ || | '--' ||  | ||__    |    \\  
\ \\___    | \_/ || | .--. ||  | ||__    | [] ||  
 \_____||   \___//  |_|| |_||  |_____||  |  __//  
  `----`    `---`   `-`  `-`   `-----`   |_|`-`   
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