21. About 15,000 years ago, northern Wisconsin ______ under ice a mile deep. A. buried B. was burying C. was buried D. had buried 22. Edward was new on the job, but he quickly fit himself into the ______ routine of the office. A. established B. establishing C. establishes D. establish 23. The Mayan Indians ______ an accurate and sophisticated calendar more than seven centuries ago. A. were developed B. developed C. are developed D. have been developed 24. George is ______ Lisa. A. marry with B. marry to C. married with D. married to 25. The rescuers ______ for their bravery and fortitude in locating the lost mountain climbers. A. were praised B. praised C. were praising D. praising 26. When I woke up and looked outside, the landscape had changed. The ground had been lightly ______ with a dusting of snow during the night. A. covering B. cover C. covers D. covered 27. We can't even walk in the storm. Let's wait in the hallway where we'll be ______ the strong winds until things quiet down. A. protected from B. protected by C. protecting from D. protecting by 28. "______ about the eight o'clock flight to Chicago?" - "Not yet. " A. Has been an announcement made B. Has an announcement made C. Has an announcement been made D. Has been made an announcement 29. Last night a tornado swept through Rockville. It ______ everything in its path. A. destroyed B. was destroyed C. was being destroyed D. had been destroyed 30. Be sure to wash the vegetables throroughly. A lot of pesticide residues ______ on unwashed produce. A. can find B. can found C. can be found D. can be finding