Which of the following is a bad habit of the executive passengers that frustrates the airlines?(  )

• A、They do not book their seats in advance.
• B、They do not sit on the seats they are supposed to take.
• C、They do not travel on the flight they have booked.
• D、They do not pay in advance for the seats they book.

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