The improvements the airlines attempt at include all the following EXCEPT   (  )

• A、making their seats more comfortable
• B、 providing better food during flights
• C、showing more movies during the long flights
• D、offering sleeperettes to first-class passengers

A. It goes like this,"A man without a smiling face must not open a shop.”

B. As luck would have it ,she sat down next t a gentleman who was more than a little distraught about the long wait for service.

C. Just what you and I would do,of course ;the smiled back at the baby.

D. No one was talking to anyone else, and all were probably thinking of a dozen other things they would rather be doing than“wasting time" sitting in that office.

E. Your smile brightens the lives of all who see it.

F. So, naturally.we are glad to see them.

16. Paragraph?17. Paragraph?

18. Paragraph?

19. Paragraph?

20. Paragraph?

A. Main Results of Recent Researches

B. Difference between Genetic and Observed Intelligence

C. Effect of Environment on Intelligence

D. Intelligence and Achievement

E. Impact on School Education

F. A Changed View of Intelligence