根据句意用所给单词的适当形式完成句子。

1. I’m sure that more and more people will celebrate their ________ (hundred) birthday.

2. There have been great ________ (improve) in both health care and personal safety.

3. Compared with the past, people are living ________ (healthy), longer lives.

4. She is very ________ (worry) about her sick father these days.

5.—What are you ________( plan)?

   —I’m thinking about giving a surprise to my mother for her birthday.