16. Many U.S cars.................. in Detroit, Michigan. A. manufacture B. have manufactured C. are manufactured D. are manufacturing 17. When I came, an experiment .................. in the lab. A. was being holding B. has been held C. was being held D. has held 18. Last night a tornado swept through Rockvill. It ............. everything in its path. A. destroyed B. was destroyed C. was being destroyed    D. had been destroyed 19. This exercise may .................. with a pencil. A. be written B. be to write C. be writing D. write 20. This picture .................... by Johnny when I came. A. painted B. was painted C. was being painted D. had been painted 21. They speak much about this book. A. This book is much spoken about. B. This book is much spoken. C. This book is much about spoken.                     D. This book are much spoken about. 22. My shirt .................. by my sister on my last birthday. A. gave B. was given C. had been given