12. Workers are building a new factory.

   => A new factory

13. We must go now because our train leaves at 8 A.M.

     => It’s

14. Although he made great efforts, he failed to win the race.

   => In spite

15. Since she was careless, Mary lost her job.

    => Because of

16.“What’s your job?” Mary asked Tom.

   => Mary wanted to know

17. I regret not paying much attention to the lecture.

  => I wish

18. Perhaps I didn’t get a better job because I didn’t study hard enough.

   => I might

19. Ms. Quyen began teaching Chinese ten years ago.

   => Ms. Quyen has

20. We haven’t visited the museum before.

   => This is