Historically, ________ main material for making tables has been wood, but ________ metal and stone have also been used.
32. Most of the audience wondered what idea a man who’s deaf from birth can have _____ music.
31. You see the lightning _____ it happens, but you hear the thunder later.
30. She had no idea how it _____ that her husband met with trouble again.
29. As far as I’m concerned, education is about learning and the more you learn, ______.
28. The Olympic Games are being _____ live to many countries.