52. 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.
37.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.
Ⅱ. Vocabulary and Structure ( 15 points ) Directions : There are 15 incomplete sentences in this section. For each sentence there are four choices marked A, B, C and D. Choose one answer that best completes the sentence and blacken the corresponding letter on the Answer Sheet. 6. Jonathan and Joe left the house to go for__ after supper.