the woman is tom's mother .the woman is curing her hair
=the woman who/that is curing her hair is tom's mother
有不会的可以再问我the english play was a great success.the students acted in it at the new year's partythe reason is that he was ill yesterday.he did not hand in his homeworkfor that reasonthe english play which/that /不填 the students acted in at the new year's party was a great successthe reason for which/why he did not hand in his homework is that he was ill yesterday.