对吸入麻醉药的概述，哪项正确（） A.凡经气道吸入而产生全身，麻醉的药物，均称吸入全

下列图像表达正确的是

A．图①表示25℃时，用0.1mol·L^－1盐酸滴定20mL 0.1mol·L^－1NaOH溶液

B．图②表示常温下，等量锌粉与足量的等体积等浓度的盐酸反应

C．图③表示向CaCl₂和盐酸的混合溶液中滴加Na₂CO₃溶液

D．图④表示向盐酸和醋酸混合溶液中滴入氨水

简述马尔柯夫过程？

小稻家的铝壶由于长时间烧水，内有一层水垢（主要含碳酸钙）在家里可选用______除垢，除垢时间不宜过长的原因是______．

第二节：完形填空（共20小题；每小题1.5分,满30分）

阅读下面短文,从短文后所给各题的四个选项(A、B、C、D)中, 选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。

Even though it was only October, my students were already whispering about Christmas plans. With each passing day everyone became more  31  , waiting for the final school bell. Upon its  32  everyone would run for their coats and go home, everyone except David.

David was a small boy in ragged clothes. I had often  33   what kind of home life David had, and what kind of mother could send her son to school dressed so  34  for the cold winter months, without a coat, boots, or gloves. But something made David 35 . I can still remember he was always  36  a smile and willing to help. He always  37  after school to straighten chairs and mop the floor. We never talked much. He  38  just simply smile and ask what else he could do, then thank me for letting him stay and slowly  39  home.

Weeks passed and the  40  over the coming Christmas grew into restlessness until the last day of  41  before the holiday break. I smiled in  42  as the last of them hurried out the door. Turning around I saw David  43  standing by my desk.

“I have something for you,” he said and  44  from behind his back a small box.  45  it to me, he said anxiously, “Open it.” I took the box from him, thanked him and slowly unwrapped it. I lifted the lid and to my  46  I saw nothing. I looked at David‘s smiling face add back into the box and said, “The box is nice, David, but it’s  47  .”

“Oh no, it isn’t,” said David. “It’s full of love. My mum told me before she died that love was something you couldn’t see or touch unless you know it’s there.”

Tears filled my eyes  48  I looked at the proud dirty face that I had rarely given  49  to. After that Christmas, David and I became good friends and I never forgot the meaning  50  the little empty box set on my desk.

31. A. anxious          B. courageous      C. serious      D. cautious

32. A. warning               B. ringing           C. calling      D. yelling

33. A. scolded          B. wondered        C. realized      D. learned

34. A. irregularly       B. unnaturally        C. untidily      D. improperly

35. A. popular          B. upset            C. special      D. funny

36. A. expressing        B. delivering        C. wearing          D. sharing

37. A. practiced          B. wandered        C. studied      D. stayed

38. A. would           B. should            C. might       D. could

39. A. aim at           B. turn to            C. put off      D. head for

40. A. argument         B. excitement         C. movement    D. judgment

41. A. school         B. year            C. education     D. program

42. A. relief                B. return             C. vain          D. control

43. A. weakly          B. sadly            C. quietly      D. helplessly

44. A. searched          B. found             C. raised       D. pulled

45. A. Holding               B. Handing         C. Sending           D. Leaving

46. A. delight          B. expectation        C. appreciation D. surprise 

47. A. cheap           B. empty            C. useless      D. improper

48. A. as              B. until            C. because      D. though

49. A. advice          B. support           C. attention      D. command

50. A. from            B. behind            C. over         D. towards

300MW机组哪些设备跳闸后RB会动作（）。

A、引风机。

B、送风机。

C、电动给水泵。

D、一次风机。