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

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Text this: Roles of carbon in light emission of ZnO