镰刀型细胞贫血症患者的血红蛋白多肽链中，一个氨基酸发生了替换。上图是该病的病因图解。

患者，男，5岁，前牙反牙合，后牙近中错牙合，反覆牙合深，反覆盖小，牙齿无松动，牙列整齐，不伴拥挤。

乳牙期矫治的目的 （）

A.促进上颌发育，抑制下颌过度发育

B.抑制上颌发育

C.美观要求

D.促进下颌发育

E.以上都不是

第二节: 完型填空（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、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。

One day I went into a shop for a specific sort of metal polish(擦光剂). While I was in the shop, I saw an older woman looking around at things, and thought I would begin a   31    to light things up. We   32   well and showed some of the beautiful items to each other. She said she was in the shop to purchase a wedding gift for a nephew, whose wedding she wouldn’t be able to attend.

We wandered off  33    and met together again at the cash register. I   34    on the beautiful bowl she had chosen, and how   35   so many of the items were. She asked what I was  36    , and I showed her my polish tube. I said I might buy more items when my kids had all    37    and gone, but they weren’t in my  38    right now. I just like to  39    , as I would do in an art museum.

She asked me what some of my   40    were, and I said I liked the salt and pepper shakers(搅拌器). She asked me to    41     her where the shakers were, so we walked over. She     42    my favorites and took them to the clerk.

I thought she was   43   with my taste, and was going to add them to her nephew’s     44   . No. They were purchased for me. They were worth ninety dollars. I couldn’t 45               it. She laughed and hugged me, and said her husband would   46   know, but she really enjoyed being able to do that    47    me. I never saw her again after that day,   48   I think of her each time I put those beautiful objects on my table.

Remembering that  49    helps me to stay aware and find opportunities to   50     to others, though not in quite such a grand way!

31. A. competition         B. research            C. secret                D. conversation

32. A. looked around    B. got on               C. gave up             D. watched out

33. A. helplessly            B. luckily                     C. separately          D. silently

34. A. depended            B. carried                     C. passed               D. commented      

35. A. lovely                 B. strange              C. expensive          D. terrible

36. A. expressing           B. thinking            C. purchasing         D. discussing

37. A. grown up            B. left                   C. cried                 D. returned

38. A. situation             B. budget                     C. favor                D. control

39. A. look                   B. complain           C. explain              D. challenge

40. A. favorites             B. duties                C. suggestions        D. habits

41. A. remind               B. prove                C. show                 D. write

42. A. turned down     B. picked up           C. laughed at         D. pointed out

43. A. pleased           B. busy                 C. careful                     D. bored

44. A. taste                   B. gift                   C. choice               D. basket

45. A. refuse                 B. change                     C. believe              D. solve

46. A. just                    B. never                C. even                 D. still

47. A. with                   B. like                   C. except               D. for

48. A. when                  B. but                   C. because             D. unless

49. A. experience          B. advice               C. mistake             D. danger

50. A. apply                  B. refer                 C. apologize          D. give

下列合同及证照中，应缴纳印花税的是( )。

A．税务登记证
B．审计咨询合同
C．贴息贷款合同
D．发电厂与电网订立的购电合同

组成病毒衣壳的成分是（）

A.核酸

B.蛋白质

C.酶

D.糖蛋白

E.脂类

重载的运算符保持其原有的 【14】 、优先级和结合性不变。