34. Scientific theories must 　　　　　facts.

33. You must use 　　　　　to open the bottle. Or you can borrow a bottle opener from the neighbor.

32. The number of people invited 　　　　fifty, but a number of them 　　　absent for different reasons.

31. Every farmer knows that weather 　　　　　farming.

30.-What did Mrs. Li say to you?

　 -- She told me 　　　　　again.

29. He asked me 　　　　I would go to Beijing by air the next day.

28. After the long journey, the three of them went back home, 　　　　　　.

27. People made voyages to conquer other parts of the world and 　　　that, English began to be spoken in many other countries.

26. It is the first time that I 　　　this strange test.　　

25. It was about 600 years ago 　　　　the first clock with a face and an hour hand was made.