系膜增生性肾小球肾炎的病理特点 A．系膜基质增生 B．系膜细胞和基质增生 C．单核细

一化学兴趣小组对某月饼包装盒中的“脱氧剂”很好奇，他们观察到“脱氧剂”外包装标注的成分为铁粉、活性炭和氯化钠，打开发现灰黑色的固体中还夹杂着少量红棕色粉末．

【资料获悉】铁系“脱氧剂”的作用原理是利用铁能被氧气氧化，从而达到除氧保鲜的目的．

【教师指导】铁被氧气氧化最终产物为红棕色的Fe₂O₃（其他产物忽略不计）．

【探究目的】小组同学欲探究该“脱氧剂”是否已经失效（即单质铁是否已经完全被氧化），并测定各成分的质量分数，设计了以下探究实验．

【实验探究】步骤1：小刚用磁铁接近样品，发现磁铁吸引了部分黑色固体．步骤2：称取10.00g样品与一烧杯中，加足量水充分搅拌溶解后，过滤，将滤渣洗涤、干燥、称得其质量为7.28g．步骤3：按如下装置，将得到的7.28g固体与足量稀硫酸反应，用电子秤称得反应前后总质量差为0.15g．

步骤4：将锥形瓶中反应后的液体过滤，并将滤渣洗涤、干燥后，称得其质量为1.20g．

【交流讨论】

（1）由步骤1得出的结论是________________________．

（2）步骤2目的是______________，检验该滤液中溶质的方法是__________________________________________________．

（3）步骤3中仪器A的名称为　__________________．小明认为0.15g差值即为H₂的质量，并 由此计算出样品中单质铁的质量为4.20g．小华提出在装置的a导管处应该再连接一个盛有碱石灰的干燥管，他这样做的理由是______________________________．

（4）如果步骤4中滤渣没有经过洗涤，则称得的质量　____　1.20g（填“＞”或“=”或“＜”）

【教师指导】样品在稀硫酸中除了Fe、Fe₂O₃分别能与稀硫酸反应外，还存在反应：Fe+Fe₂（SO₄）₃=3FeSO₄．因此，小明用产生H₂的质量计算样品中铁的质量不合理．实际上，样品中单质铁的质量应该是与酸反应消耗的铁和与Fe₂（SO₄）₃反应消耗铁的质量总和．

【学生实验】小红将步骤3的装置进行了改进，重新称取10.00g样品进行实验，并准确测得固体与足量稀硫酸反应前后总质量差为0.14g．

【数据处理】由于反应过程较复杂，小组同学在老师的帮助下，推算出与Fe₂（SO₄）₃反应消耗铁的质量为0.56g．

【请你参与】（1）写出Fe₂O₃与稀硫酸反应的化学方程式．（2）请根据以上数据，计算该样品中各成分的质量分数．

第二节完形填空(共20小题,每小题1.5分，满分30分)

阅读下面短文，从短文后所给四个选项(A、B、C和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。    ‘

In the wake Of Chicago's worst ever winter，it snowed heavily for almost  10 days off and on，until all of the rooftops were loaded，many overloaded，with snow．Robert McGrath saw  36  run out to the  37   to fetch some boxes.

Seconds   38  while he was  39 on his work，he heard a crash!

  40 ，he saw the roof of the garage bad  41  in. McGrath did not stop to put his hat or coat on. He 42 out of the house．grabbed a snow shovel，and called    43  for his neighbors to come and help.

Yelling and digging，with   44  freezing on his face-clearing snow，pulling   45  

boards and anxiously calling his wife's name---he heard her   46  and then saw he hand. He kept digging，clearing and pulling...

Within   47  he had his wife in his arms and was sobbing，"Are you all right? Are you all right? I   48  you were dead．On baby，I love you so much!”She was  49   .

What Robert McGrath did NOT know was this：Mrs. McGrath had gone into the garage  50 one door and out through another. She was   51  in the house when she heard her husband's voice.   52  she went to the window to took out and saw her husband digging and shouting her  53  and pulling out planks of wood，feverishly trying to rescue her. She could not let her gallant rescuer   54  .So she put her coat on again，went outside and quietly entered the garage through the back door----and   55   her husband to be her hero.

36. A. his friend        B. his wife         C. his neighbor       D. a stranger

37. A. garage          B．garden         C．store            D. kitchen

38. A. ago             B. before          C. later             D. after

39. A. paying          B. confusing        C. drawing          D. focusing

40. A. Looking out      B. Rushing out      C. Getting out       D. Coming out

41. A. made           B. fallen           C. pulled            D. let

42. A．found          B. walked          C. rushed           D. showed

43. A. proudly         B. kindly           C．friendly         D. loudly

44. A．snow          B. ice              C. sweat            D. water

45. A. down           B. away            C. on             D. toward

46. A. voice           B. sound            C. noise            D. name

47. A. minutes         B. days             C. hours            D. time

48. A. intended        B. wondered         C. thought           D. considered

49. A．hurt           B. wounded          C. frightened        D. fine

50. A. around          B. through           C. into             D. past

51. A. safe            B. quiet             C. peaceful          D. worried

52. A. However        B. Or               C. But             D. So

53. A. helps           B. mothers           C. name            D. neighbors

54. A. up             B. down             C. out               D. in

55. A. allowed         B. made             C. advised            D. Persuaded

α螺旋和β折叠是蛋白质的二级结构。

两种色块或两种以上的色块反复出现在画面上叫（），它是一种特殊的画面协调方式。

A.混合

B.并置

C.对比

D.和谐

如发现细小文字有锯齿状应如何处理？（）

A.可用补版胶修补

B.可用修整胶修补

C.加强晒版补强

D.已很难补救