请教Linq

[leon51]

请问如何用Linq取出下面所有LAYER_POSITION等于"Outer Layer"的“OVERALL_THICKNESS”和“MIN_TRACE_WIDTH”的值，谢谢！

	<COPPER_LAYERS>
		<COPPER_LAYER NAME="L1"
		 OVERALL_THICKNESS="1.815655396"
		 MIN_TRACE_WIDTH="5"
		 LAYER_POSITION="Outer Layer"
		>
		<ACCESSORIES>
		</ACCESSORIES>
		<APPROVALS>
		</APPROVALS>
		<MASK_LAYER>
			<REF
			 NAME="sc"
			/>
			<REF
			 NAME="lc"
			/>
		</MASK_LAYER>
		</COPPER_LAYER>
		<COPPER_LAYER NAME="L2"
		 OVERALL_THICKNESS="1.2"
		 MIN_TRACE_WIDTH="0"
		 LAYER_POSITION="Inner Layer"
		>
		<ACCESSORIES>
		</ACCESSORIES>
		<APPROVALS>
		</APPROVALS>
		<MASK_LAYER>
		</MASK_LAYER>
		</COPPER_LAYER>
		<COPPER_LAYER NAME="L3"
		 OVERALL_THICKNESS="1.2"
		 MIN_TRACE_WIDTH="6"
		 LAYER_POSITION="Inner Layer"
		>
		<ACCESSORIES>
		</ACCESSORIES>
		<APPROVALS>
		</APPROVALS>
		<MASK_LAYER>
		</MASK_LAYER>
		</COPPER_LAYER>
		<COPPER_LAYER NAME="L4"
		 OVERALL_THICKNESS="1.815655396"
		 MIN_TRACE_WIDTH="0"
		 LAYER_POSITION="Outer Layer"
		>
		<ACCESSORIES>
		</ACCESSORIES>
		<APPROVALS>
		</APPROVALS>
		<MASK_LAYER>
			<REF
			 NAME="ss"
			/>
			<REF
			 NAME="ls"
			/>
		</MASK_LAYER>
		</COPPER_LAYER>
	</COPPER_LAYERS>

[github_36000833]

var root = XElement.Parse(xml);
var selections = root.Elements().Where(x => x.Attribute("LAYER_POSITION")?.Value == "Outer Layer");
foreach(var selected in selections)
{
    Console.WriteLine("{0} {1}", selected.Attribute("OVERALL_THICKNESS")?.Value, selected.Attribute("MIN_TRACE_WIDTH")?.Value);
}