We laugh at jokes，but seldom____________about how they work．

   A．we think         B．think we       C．we do think        D．do we think

We laugh at jokes, but seldom __________ about how they work.

We laugh at jokes, but seldom __________ about how they work.

We laugh at jokes，but seldom ????????? about how they work．

A．we think???????? B．think we?????? C．we do think??????? D．do we think

Laugh and the world laughs with you. Even better, you might live longer, an American researcher reports.

“Adults who have ___1.___ sense of humor live longer than those who don’t find life funny, and the survival edge is ___2.__ (particular) large for people ___3.___ cancer,” says Richard Smith of the Columbia University of Science and Technology.

He ___4.___ (present) his study of about 54,000 Americans, ___5.___ he had followed for seven years, at the American Psychosomatic Society meeting last Monday.

At the start, patients filled out questionnaires on how easily they found humor in real-life situations __6.___ how important a ___7.___ (humor) idea was.

The study showed next the greater role humor played in their lives, the greater their chances were in ___8.___（survive）the seven years. Adults scoring in the top one-quarter for humor appreciation were 35% more likely to be alive ___9.__ those in the bottom quarter. In a smaller group of 2,015 people who had a cancer diagnosis(诊断) at the start, the study found ___10.__ important that a great sense of humor cut the chances of dying by about 70%.