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.

Why is debate important？

• A、It helps people understand others better.

• B、It allows people to present their opinions.

• C、It develops one' s thinking and communicative competence.

• D、It gives one the opportunity to brush others' opinion aside.

你是王剛(Wang Gang)，寫(xiě)一封給朋友李明(Li Ming)的祝賀信，祝賀他獲得復(fù)旦大學(xué)計(jì)算機(jī)科學(xué)碩士學(xué)位，并祝他今后在學(xué)習(xí)和研究方面取得成功。