The mother asked her son to help her because she had ________ in sending e - mails．
A.some difficulties
B.many difficulties
C.a difficulty
D.some difficulty
网友回答
D解析difficulty表示“困难”，用作抽象概念，是不可数名词的用法，而用作表示“各种各样的困难”就是可数名词的用法。但在词组中，difficulty用作不可数名词，have some difficulty in doing sth表示“做某事有一些困难”。这句句子的意思是“这个母亲叫孩子来帮她，因为她在发e - mail邮件时有点困难。”