blotch [blɑ:tʃ]

例句:

• 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.
  
• In this paper , the occurrence of watermelon bacterial fruit blotch was first reported in Jilin province.
  首次报道了西瓜细菌性果斑病在吉林省的发生.
  
• Now he finds himself out of work and with the first big blotch on his copybook.
  来自BBC