你是王剛(Wang Gang)，寫一封給朋友李明(Li Ming)的祝賀信，祝賀他獲得復旦大學計算機科學碩士學位，并祝他今后在學習和研究方面取得成功。

What does the underlined word "centenarians" in Paragraph 1 refer to?

• A、People who have secret lifestyles.

• B、People who enjoy physical exercise.

• C、People who are one hundred years old or older.

• D、People who carry the gene for being slim.

The president is to give a formal __ at the opening ceremony.

• A、speech

• B、debate

• C、discussion

• D、argument