沼渣、沼液肥种梨应掌握哪些技术要点?

题型:问答题 简答题

问题:

沼渣、沼液肥种梨应掌握哪些技术要点?

考点:沼气生产工沼气生产工题库
题型:问答题 简答题

在如图所示电路中,电源电压可在3~6伏范围内调节.

①当通过滑动变阴器R2的电流为0.4安时,R2两端的电压为2伏,求变阻器R2连入电路的阻值.

②若要使电路中电流可在0.2~0.6安范围内调节.求所用定值电阻的最大阻值R1

③现有标有“10Ω2A”、“20Ω0.5A”和“50Ω1A”字样的变阻器各一个,当电源电压为6伏且不变时,请选择符合电路电流及电阻R1最大阻值要求的变阻器.

(a)选择标有______字样的变阻器.

(b)求出所选用的变阻器连入电路的阻值范围.

题型:问答题 简答题

茶香物质的组成特点?

题型:问答题 简答题

头孢菌素族的母核结构部分

A.费休法
B.铂电极
C.汞-硫酸亚汞电极
D.萘
E.青霉素V

题型:问答题 简答题

第二节完形填空(共20小题;每小题1.5分,满分30分)

Wishing to encourage her young son’s progress on the piano, a mother took her boy to a famous concert. After they were seated, the mother  36    a friend and walked over to greet her. Seizing the  37  to explore the wonders of the concert hall, the little boy got up and explored his way 38   a door marked “NO ADMITTANCE(禁止进入)”. When the lights became less bright and the concert was about to begin, the mother returned to her  39    and discovered that the child was missing.

Suddenly, the curtains  40  and the lights focused on the stage. In horror, the mother saw her little boy sitting at the keyboard,   41  Twinkle, Twinkle, Little Star.

At that moment, the great piano master, Paderewski,  42  on the stage, quickly went to the piano and  43  in the boy’s ear, “Don’t  44  . Keep playing.”

Then, leaning(倾斜) over, Paderewski reached down with his left hand and began  45  in a bass (低音的) part. Soon his right arm reached  46  to the other side of the child and he added a beautiful piece of music.  47  , the old master and the boy  48   a frightening situation into a wonderfully creative  49 

That’s the way it is in life.  50  we can complete on our own is  51  noteworthy(值得注目的). We try our best, but the 52  aren’t exactly graceful or flowing music.  53  when we put our trust in the hands of greater power, our life can be truly beautiful.

The next time you set  54  to create great performances, listen carefully. You can hear the  55  of the master whispering in your ear, “Don’t quit. Keep playing.”

36. A. made           B. saw               C. looked           D. called

37. A. chance     B. performance   C. piano       D. lesson

38. A. over            B. above        C. across       D. through

39. A. stage           B. seat              C. room       D. table

40. A. parted          B. drew        C. pulled      D. pushed

41. A. singing     B. knocking      C. playing      D. creating

42. A. stood           B. appeared     C. sat         D. fell

43. A. shouted     B. cried        C. whispered    D. looked

44. A. perform          B. stop             C. leave       D. run

45. A. filling          B. getting       C. breaking      D. taking

46. A. forwards      B. down       C. up          D. around

47. A. Separately  B. Together       C. Luckily     D. Hurriedly

48. A. made           B. became        C. changed           D. grew

49. A. experience  B. play          C. concert      D. film

50. A. What           B. That          C. Which      D. When

51. A. hard            B. hardly        C. always      D. usually

52. A. failures     B. successes     C. causes       D. results

53. A. So           B. And         C. But          D. Though

54. A. down           B. about       C. away        D. out

55. A. sound          B. noise        C. voice        D. song

题型:问答题 简答题

间隙相的性能特点是()。

A.熔点高、硬度低

B.硬度高、熔点低

C.硬度高、熔点高

更多题库