如图甲所示，线圈与电压传感器连接，一条形磁铁从线圈上方某一高度无初速释放并穿过线

二氧化碳泡沫灭火器的原理，是利用物质反应时生成的二氧化碳，与加入的发泡物质产生大量泡沫，喷出灭火。小明用废旧塑料制品自制了一个泡沫灭火器，如下图所示。

(1)塑料属于_________材料。

(2)小明家里有下列物质：醋、厕所清洁剂、厨房清洁剂、纯碱、小苏打、石灰石块、洗沾精、洗衣粉等，你认为小明可以选用的一组物质是___________。

(3)水和泡沫喷洒在燃烧物上能够灭火，其原理是：_______________。

       he       America?[ ]

A. Is, come from                              

B. Does, comes from

C. Is, comes from                              

D. Does, come from

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，从短文后所给各题的四个选项(A、B、C和D)中，选出可以填入空白处的最佳选项。

Many facts suggest that children are overweight and the situation is getting worse, according to the doctors. I feel there are  36  reasons for this.

Some people blame the fact  37   we are surrounded by shops selling unhealthy, fatty foods,  _38  fried chicken and ice cream,  39  low price. This has turned out a whole generation of grown-ups  40  seldom cook a meal for themselves. If there  41  fewer of these restaurants, then probably children would buy less take-away food.

There is another argument that  42  parents for allowing their children to become overweight. I _43  this, because good eating habits begin early in life, long before children start to visit fast food shops. If children are given fried chicken and chocolate  44  healthy food, or are always allowed to choose  45  they eat, they will go for sweet and salty foods every time, and this  46  throughout their lives.

There is a third reason for this situation. Children these days  47  very little exercise. They do not walk to school. When they  48  home, they sit in front of  49  or their computers and play computer games.  50  is this an unhealthy pastime (消遣),it also gives them time to eat more  51  food.  52  they need is to go outside and play active games or sports.

The above  53   the main reasons for this problem, and therefore we have to  54  young people to be more active, as well as steering them away from fast food shops and  55 eating habits.

36. A. much               B. a number of       C. amount of               D. lot of

37. A. which              B. what             C. that                    D. whose

38. A. such as             B. so that            C. such that                 D. and so on

39. A. with                B. on                C. at                        D. to

40. A. which              B. whose              C. where                  D. who

41. A. were              B. was               C. is                    D. are

42. A. blame              B. blames            C. ask                    D. tell

43. A. agree on            B. agree at           C. agree in                 D. agree with

44. A. as well as            B. besides            C. rather than                      D. beside

45. A. that                B. what             C. which                   D. when

46. A. carry on            B. will carry out      C. will carry on                    D. carry off

47. A. take                B. go               C. walk                    D. jump

48. A. get to              B. go to                     C. arrive at                        D. get

49. A. the book            B. the television       C. the homework            D. the telephone

50. A. Either              B. And              C. Not only                 D. If

51. A. healthy             B. cold               C. delicious                D. unhealthy

52. A. What                B. That              C. Which                   D. Where

53. A. is                 B. are                C. was                    D. were

54. A. order              B. tell                     C. encourage               D. inform

55. A. good               B. healthy            C. nice                    D. bad

混凝土和砂浆用再生细骨料粗规格的细度模数是（）？

A、3.7~3.1

B、3.0~2.3

C、2.2~1.6

D、1.5~0.8