1-5 DDACA 6-10 ACAAC
11-15 BCDBC16-20 FBGCD
21-25 CBDAC 26-30ADBBD
31-35 CACBD 36-40ADACB
41. called 42. visited
43. to leave 44.decision
45. terribly 46.of
47. eating 48.the
49. pieces 50.that / which
51. ... pay for that ... that → what
52. ... remove some item ... item → items
53. ... another shopper hands ...
hands → handed
54. Having refused by ...refused前加been
55. ... was serious ill ... serious → seriously
56. ... brought herself several ...
herself → her
57. ... went to there ... 去掉to
58. ... for spend too ... spend → spending
59. ... demanded he did ... did → do
60. ... for their kind. kind → kindness
One possible version:
Dear Mr and Mrs Smith,
I'm writing to tell you that I have returnedhome safely. It was because of your help that I had a wonderful time in London.Thank you very much.
When I think of the wonderful time I spent inLondon I can't help thinking of both of you. It was very kind of you to havetaken good care of me. I have learned so much about not only the Englishlanguage, but also British culture. Moreover, I really enjoyed the fun andlaughter we shared with each other. I'll always remember this trip and yourkindness.
I hope you will come to visit China someday soI can return your kindness.
1-4 BCDB 5-8 ABAA
2.C。细节理解题。根据第四段中的All of them majored in science subjects可知，这些志愿者都是有科学教育背景的。
3.D。细节理解题。根据倒数第二段中的the team has reached more than 300,000 students and visited morethan 2,600 schools可知，这一组织已经帮助了2600多所学校的30多万名学生。
4.B。推理判断题。根据最后一段中的Many primary school students have never seen a microscope or anyother laboratory equipment可知，许多小学都缺乏相应的实验设备。
5.A。细节理解题。根据第二段中的But all this is about to change — thanks to theamount of plankton found in UK waters at this time of year及第三段的内容可知，英国海域丰富的浮游生物吸引来了姥鲨，这使得人们对姥鲨的研究变得容易。
7.A。细节理解题。根据倒数第三段中的The results gathered from tagging in areas such as Porthcurno andSennen Cove will be used as the basis for a plan to protect the sharks可知，研究人员收集姥鲨的信息是为了更好地了解它们并保护它们。
8.A。推理判断题。根据最后一段中的Unlike traditional tags, which can pinpoint the shark to within akilometre, the new equipment can locate the creature to within metres可知，新技术可以为研究者提供更精确的定位信息。