问题 计算题

钛合金的密度约为4.5g/cm3,强度可与钢材相比,抗腐蚀性能好,具有多次锻打加工的性能好等优点,是较为理想的航天工程材料。例如美国的B-1轰炸机的机体结构材料中,钛合金约占21%,主要用于制造机身、机翼、蒙皮和承力构件。随着技术发展,钛合金进入普通百姓家庭,钛合金的眼镜架显得高贵典雅。

(1)飞机上用钛合金代替钢材利用了哪些物理性质?

(2)一个质量为20g,密度为8×103kg/m3的铜铁合金眼镜架,若改用钛合金来制作(体积不变),可以减轻多少克?

答案

(1)密度小、硬度大、延展性好等

(2) 8.75g

简答题
完形填空

第二节:完形填空(共20小题,每小题1.5分,满分30分)

BRITISH newspapers are among the oldest and most famous in the world. But recently big changes have   36   these traditional publications try to  37  the modern world. After 216 years, The Times has halved its   38   to become much smaller. In fact, the paper has  39  its size in half from a broadsheet to tabloid(小型报纸).

In Britain the newspaper market is  40  between the larger broadsheets and the smaller tabloids. These terms  41  the size of the papers' pages but there is also a clear  42  in content. Broadsheets such as The Times, the Guardian and Daily Telegraph are  43  papers. They  44  a broad range of political, economic and international issues. Their stories are also  45  long and use quite formal language.

Tabloids have  46  more stories about less serious issues such as celebrities' love lives. Their stories are shorter and use more  47  language. Tabloids often have bigger pictures. Britain's  48  newspaper, the Sun, is a tabloid and has a naked page on page three every day.

By  49  to the size of a tabloid, The Times is following in the  50  of a less famous broadsheet paper, the Independent. It changed to tabloid last year and saw its sales increase  51 . Although both papers have   52   to the smaller size, the content of the papers has  53  the same. They are both still serious papers.

The two papers  54  that people find the smaller size easier to  55  when they travel to work on the bus or the train in the morning. The times says its new size is "compact", not tabloid.

36. A. found                   B. known                C. seen                   D. proved

37. A. match                    B. suit                     C. change                D. fit

38. A. length                       B. thickness             C. width                         D. size

39. A. printed                 B. cut                        C. added                       D. enlarged

40. A. divided                  B. separated                  C. arranged                D. marked

41. A. turn into                 B. think about               C. refer to                    D. connect with

42. A. meaning                  B. difference             C. mark                        D. sign

43. A. useful                        B. easy                    C. serious                  D. long

44. A. sell                       B. include                    C. take                      D. cover 

45. A. certainly             B. reasonably                      C. probably                D. necessarily

46. A. a few                        B. little                        C. far                           D. any

47. A. difficult                        B. simple                 C. easy                        D. good

48. A. best-selling                B. good-looking            C. slow-moving            D. ugly-looking

49. A. going                    B. getting                   C. coming                    D. changing

50. A. footsteps                       B. way                    C. direction                  D. method

51. A. slowly                    B. usually                    C. little                    D. greatly

52. A. halved                    B. made                   C. changed                 D. cut

53. A. become                   B. remained              C. left                   D. found

54. A. agree                     B. hope                    C. expect                 D. insist

55. A. handle                       B. look                         C. see                           D. buy