5594In the late 1960s , motorcyclists in California , USA , （16 ) to go out in the countryside and ride their machines up and down mountain tracks just for fun. They made （17) noise and did a lot of dama5521

16. A. had been used B. has been used C. used D. was used 17. A. many B. much C. any D. some 18. A. as well B. either C. too D. as well as 19. A. was born B. is born C. were born D. are born 20. A. when B. how C. which D. where