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

The following are all mentioned as reasons why the airlines are having a hard time EXCEPT that     .(  )

• A、the tourist industry is experiencing an all-time low
• B、there is no increase in the number of passengers
• C、there are more seats on the planes than needed
• D、the competition between airlines is strong

Among the early settlers in South America in the 16th century were Spanish traders.(  )

• A、Right
• B、Wrong
• C、Not mentioned