听力ceramic制作历史

31. ceramics date back approximately (a)   .

32. The first figurines were made in the area of (a)   .

33. early humans could not use their pots to store (a)   .

34. The Chinese improved the quality of ceramics by mixing (a)   with the clay.

35. Chinese porcelain was also called (a)   .

36. Bottger added quartz and (a)   to clay to make porcelain.

37. Glass production is similar to clay ceramics apart from the rate of (a)   .

38. the romans introduced the use of glass to make (a)   .

39. the discovery of concrete is probably due to observing reactions of water and (a)   .

40. the ability to build large (a)   contributed to the success of the Roman Empire.