阅读下面短文，掌握其大意，然后从各题所给的四个选项中选出可以填入空白处的最佳选项。

Mrs White is my neighbour and she is over seventy now, but she is still very ___. Every morning she gets up early and ___ some exercise in the park near our community. She is always ready to help others. Last winter my mother was ill and Mrs White ___ after my little sister for a whole week. We were all very ___ to her for what she had done. She often says with a smile that helping others makes her ___(5).

【第5空】