小题1:A
小题2:D
小题3:A
小题4:D
小题5:C
文章主要告诉我们光阴的珍贵, 我们应该做好每个年龄段应该做的事。
1. A。事实细节题。从Children is a time when there are few responsibilities to make life difficult可知答案A正确。
2. D。推理判断题。从When the young man starts to earn his own living, he can no longer expect others to pay for his food, his clothes, and his room, but has to work if he wants to live comfortably可知每个孩子长大后都应该学会自己照顾自己，即答案选D。
3. A。推理判断题。文章讲到世界对小孩子来说是新鲜有趣的, 对老人来说是熟悉的, 未含有人们容易满足的这一意思，故此题答案选A。
4. D。主旨大意题。文章第 1 段点明文章主旨即什么年龄段做什么事是最快乐的事，即答案D正确。
5. C。推理判断题。从文章第 1 句How often one hears children wishing they were grown up, and old people wishing they were young again可知文章谈完儿童时期，将接着谈老年时期。故答案选C。