The trousers have doublethickness knee panels for extra protection.
这条裤子上有双倍厚的护膝片以加强保护。
《牛津词典》
2
Form a doublethickness of heavy-duty foil (about 14 in. square); cut three slits in foil.
做一个双层金属箔(大约14英寸见方),在上面划三道口。
3
Each sensitive area provides a double textile thickness, featuring a highly resistant textile film in between two layers, which ensures even weight distribution.