1. It seems certain that they have made a series ofexperiments.

2. It is said that bats have been using radar formillions of years.

3. To tell the truth , many mistakes we made could havebeen avoided.

4. As we know, it was not until recently that the problemwas solved.

5. It must be admitted that you haven't done what youpromised to do.

6. It is a common saying that man who has a settledpurpose will surely succeed.

7. It is clear that the enemy has no desire for peace.

8. It is hard to imagine how Edison managed to worktwenty hours each day.

9. It's hard to say whether the plan is practicable.

10. There is no doubt that you will be helped by othersif you have any difficulties.

11. The oceans do not so much divide theworld as unite it.

12. There is no denying the fact that the new managementmethod has greatly increased the production.

13. There is no denying the fact that the new managementmethod has greatly increased the production.

14. Upon hearing the unexpected news, he was so surprisedthat he couldn't utter a word.

15. As the saying goes, nothing in the world is difficultfor one who sets his mind to it.

16. In my opinion, this computer is different from thatone you saw.

17. It is certain that we have a long way to go.

18. All this shows that nothing can prevent us fromreaching our aims.

19. As far as we know, it took him more than a year towrite the book.

20. It has been proved that every substance, no matterwhat it is, is made up of atoms.

21. It must be pointed out that it is one of our basicState policies to control population growth while raising the quality of thepopulation.

22. It is (has been) estimated that the world'spopulation could reach 6 billion by the end of the century.

23. It must be kept in mind that there is no secret ofsuccess but hard work.

24. It can be seen from this that there is no difficultyin the world we cannot overcome.

25. As is known man is the product of labour.

26. Our goal must be attained. Our goal canunquestionably be attained.

27. Noting can prevent us from realizing the fourmodernizations.

28. Now in China, more and more families can afford tobuy high-grade goods, such as washing machines, TV sets, videocorders.

29. No matter how difficult English may be, you should doyour best to learn it.

30. It can be said that without knowledge of science andtechnology, it is impossible to build socialist modernizations.

31. It has been decided that we are going to build arailway whose base must be completed within this year.

32. It is obvious (evident) that the success of theinnovation depends on our concerted efforts.

33. To be frank, whether you like it or not, you have noother choice.

34. It is natural that one may have trouble expressingcomplicated ideas in simple English.

35. What is more important, the agreement they havenegotiated is being carried out.

36. We will be successful as long as we persevere.

37. Frankly speaking, what you call the truth may notapply to things happening here.

38. It is true that we must redouble our efforts;otherwise we cannot catch up with the developed countries.

39. I take it for granted that they will support thisidea.

40. In a certain sense, a successful scientist is aperson who is never satisfied with what he has achieved.