25. He ______ his head, wondering how to solve the problem.
A) scrapped
B) screwed
C) scraped
D) scratched

26. As soon as the boy was able to earn his own living he ______ his parents' strict rules.
A) defied
B) refuted
C) excluded
D) vetoed

27. The helicopter _____ a light plane and both pilots were killed.
A) coincided with
B) stumbled on
C) tumbled to
D) collided with

28. To ______ is to save and protect, to leave what we ourselves enjoy in such good condition that others may also share the enjoyment.
A) conserve
B) conceive
C) convert
D) contrive

29. Put on dark glasses or the sun will ______ you and you won' t be able to see.
A) discern
B) distort
C) distract
D) dazzle

30. In ______ times human beings did not travel for pleasure but to find a more favourable climate.
A) prime
B) primitive
C) primary
D) preliminary