According to the passage, in operating airlines it is essential to     .(  )

• A、keep in mind the need. of the executives only
• B、satisfy the need of the low fare passengers at the expense of the executives
• C、try to attract as many passengers as possible by reducing fares
• D、cater to the need of passengers setting at both ends of the jets

21. It was once believed       ,and thus we can tell how successful he/ she will be in the future according to his/her intelligence.

22. More recent researches has shown that intelligence is only partly inherited      .

23. We. can observe and measure observed intelligence, but genetic intelligence      .

24. It can be inferred from the passage that a child will      if he has more opportunities to communicate with others by means of language.

25. Children were not just      ,but they can be taught to be more intelligent at school.

A. born to be more intelligent or less intelligent

B. have 8 better chance to develop, his intelligence

C. can't be observed and measured

D. that intelligence was something a baby was born with

E. and because of the lack of communication with his classmates

F. and partly has to do with a child's living environment

We know for sure that colonization began at the end of the 15^th century.(  )

• A、Right

• B、Wrong

• C、Not mentioned