题目内容：

parents are taking good care of us and doing a lot for us in our daily life ,as ---- only child ,i should remember the word of thanksgiving and do something grateful for them
A an B the 选哪个 为什么

优质解答

选A
an和the都是惯词
一般前文没有提到的,不是特指某一个东西的,用a或an（there is an apple）
如果特指某一样东西,要用the（the apple is mine）