阅读下列四篇短文，从每小题后所给的A,B,C或D四个选项中，选出最佳选项。
How is it that siblings (兄弟姐妹) can turn out so differently? One answer is that in fact each sibling grows upin a different family. The firstborn is, for a while, an only child, and therefore has a completely different experience of the parents than those born later. The next child is, for a while, the youngest, until the situation is changed by a new arrival. The mother and father themselves are changing and growing up too. One sibling might live in a stable and close family in the first few years; another might be raised in a family crisis, with a disappointed mother or an angry father.
