blotch的复数形式怎么写？

n.（皮肤上的）红斑，疹块，大滴 [大片]（墨水或颜色的）污渍vt.使沾上污渍，弄脏...

blotch的音标：blotch的英式发音音标为：[blɒtʃ]blotch的美式发音音标为：[blɑtʃ]...

His face was covered in ugly red blotch es.他脸上有许多难看的红色大斑点.But there had no blotch in negative control.而阴性(空白)对照则相对应位置上无斑点....