We have done a lot of trade with your company for the past five years.

A、market maker.

B、transaction broker.

C、content disseminator.

D、viral marketer.

Not all metals have unit cells with cubic symmetry; the final common metallic crystal structure to be discussed has a unit cell that is hexagonal. Figure 3.3a shows a reduced-sphere unit cell for this structure, which is termed hexagonal closepacked (HCP);an assemblage of several HCP unit cells is presented in Figure 3.3b. The top and bottom faces of the unit cell consist of six atoms that form regular hexagons and surround a single atom in the center. Another plane that provides three additional atoms to the unit cell is situated between the top and bottom planes. The atoms in this midplane have as nearest neighbors atoms in both of the adjacent two planes. The equivalent of six atoms is contained in each unit cell; one-sixth of each of the 12 top and bottom face corner atoms, one-half of each of the 2 center face atoms, and all 3 midplane interior atoms. If a and c represent, respectively, the short and long unit cell dimensions of Figure 3.3a, the c/a ratio should be 1.633; however, for some HCP metals this ratio deviates from the ideal value.

A、chain writing

B、sequencing

C、scaffolding

D、checklists

A、连词

B、同义词

C、近义词

D、上下义词

During recent years we have heard much about “race”: how this race does certain things and that race believes certain things and so on. Yet, the __41__ phenomenon of race consists of a few surface indications.

We judge race usually __42__ the coloring of the skin: a white race, a brown race, a yellow race and a black race. But __43__ you were to remove the skin you could not __44__ anything about the race to which the individual belonged. There is __45__ in physical structure. The brain or the internal organs to __46__ a difference.

There are four types of blood. __47__ types are found in every race, and n o type is distinct to any race. Human brains are the __48__. No scientists could examine a brain and told you the race to which the individual belonged. Brains will __49__ in size, but this occurs within every race. __50__ does size have anything to do with intelligence. The largest brain __51__ examined belonged to a person of weak __52__. On the other hand, some of our most distinguished people have had __53__ brains.

Mental tests which are reasonably __54__ show no differences in intelligence between races. High and low test results both can be recorded by different members of any race. __55__ equal educational advantages, there will be no difference in average standings, either on account of race or geographical location.

Individuals of every race __56__ civilization to go backward or forward. Training and education can change the response of a group of people, __57__ enable them to behave in a __58__ way.

The behavior. and ideas of people change according to circumstances, but they can always go back or go on to something new __59__ is better and higher than anything __60__ the past.

41. a. complete b. full c. total d. whole

42. a. in b. from c. at d. on

43. a. since b. if c. as d. while

44. a. speak b. talk c. tell d. mention

45. a. something b. everything

c. nothing d. anything

46. a. display b. indicate c. demonstrate d. appear

47. a. All b. Most c. No d. Some

48. a. same b. identical c. similar d. alike

49. a. remain b. increase c. decrease d. vary

50. a. Only b. Or c. Nor d. So

51. a. ever b. then c. never d. once

52. a. health b. body c. mind d. thought

53. a. big b. small c. minor d. major

54. a. true b. exact c. certain d. accurate

55. a. Provided b. Concerning

c. Given d. Following

56. a. make b. cause c. move d. turn

57. a. and b. but c. though d. so

58. a. ordinary b. peculiar c. usual d. common

59. a. that b. what c. whichever d. whatever

60. a. for b. to c. within d. in