Mother's day is just round the cornen.I want to buy a present for my mother,one that is useful but not espensive.It seems that the news that her husband had an accident was ture.one和news同样有同位语从句修饰,为什么one前无定冠词而n

Mother's day is just round the cornen.I want to buy a present for my mother,one that is useful but not espensive.It seems that the news that her husband had an accident was ture.one和news同样有同位语从句修饰,为什么one前无定冠词而n
Mother's day is just round the cornen.I want to buy a present for my mother,one that is useful but not espensive.
It seems that the news that her husband had an accident was ture.
one和news同样有同位语从句修饰,为什么one前无定冠词而news前有?

Mother's day is just round the cornen.I want to buy a present for my mother,one that is useful but not espensive.It seems that the news that her husband had an accident was ture.one和news同样有同位语从句修饰,为什么one前无定冠词而n
第一句中的one 是不定代词,也就是说这个礼物是不确定的,只要有用并且不要太贵就可以了.
第二句中的news是确定的,即她丈夫出事故的消息,因此要加the

one是代词，news是名词。
像one，this，that，it，some，another等代词前都不用the