C
China's space station orbits（沿轨道运行） about 400 to 450 kilometers from the Earth. It's designed to last for 10 years.
51. The weight of the station can reach about 180,000 kilos.
In June 2021, three taikonauts of Shenzhou 12 manned spacecraft（载人航天器） entered the space station. 52. Since then,
more and more taikonauts have gone to the station to do research.
53. It could rise quickly to $150°\mathrm{C}$ in direct sunlight and drop to $-100°\mathrm{C}$ in darkness. The scientists use a thermal（热量的） control system to keep the taikonauts safe from extreme（极端的） temperature. Thanks to the thermal control system, the temperature in the space station is neither too cold nor too hot. 54.
Plants play a key role in scientists' research on life-support systems. For taikonauts, growing vegetables in the space station can not only help study the effects of special space environment, but also reduce（减少） their own stress and make them feel comfortable. 55. Those plants play an important role in setting up a life support system in space, greatly reducing the costs for long-term manned missions（任务）.

51. A 52. B 53. E 54. C 55. D

【分析】
这是一道句子还原题，需结合上下文的话题连贯性、逻辑关系解题。先通读全文，明确文章围绕中国空间站展开，依次介绍空间站的容量、首次航天员进入情况、温度问题及解决、植物在空间站的作用。
步骤1：分析51题，前文介绍空间站基本情况，后文提及空间站重量，选项A描述空间站容纳航天员的数量，符合容量特征，衔接合理；
步骤2：分析52题，前文说明2021年三名航天员进入空间站，后文提到更多航天员后续前往，选项B说明这是首次航天员进入，解释了后续情况的背景；
步骤3：分析53题，后文详细描述空间站温度的极端变化，选项E引出“空间站温度是大问题”的话题，与后文内容呼应；
步骤4：分析54题，前文提到温度控制系统让空间站温度适宜，后文转向植物在空间站的作用，选项C衔接温度适宜与植物生长的话题；
步骤5：分析55题，前文说明在空间站种蔬菜的好处，后文提到植物对生命支持系统的作用，选项D补充植物的另一重要作用，衔接自然。
【解析】
51. 前文介绍中国空间站的基本情况，后文提到空间站重量，选项A“Three taikonauts can live in it at a time.”（一次可容纳三名航天员）符合空间站的容量描述，衔接上下文，故51选A。
52. 前文说明2021年6月三名航天员进入空间站，后文提到“Since then, more and more taikonauts have gone to the station to do research.”，选项B“That was the first time for taikonauts to get into the station.”（那是航天员首次进入空间站）解释了后续更多航天员前往的背景，故52选B。
53. 后文详细描述空间站温度的极端变化（150℃和-100℃），选项E“It's a big problem to deal with the temperature in the space station.”（处理空间站的温度是个大问题）引出温度话题，与后文内容呼应，故53选E。
54. 前文提到温度控制系统让空间站温度适宜，后文转向植物在空间站的作用，选项C“And the temperature allows the vegetables to grow well.”（温度允许蔬菜长得好）衔接温度适宜与植物生长的话题，故54选C。
55. 前文说明在空间站种蔬菜的好处，后文提到植物对生命支持系统的作用，选项D“More importantly, they can also get food and water this way.”（更重要的是，他们也可以通过这种方式获得食物和水）补充植物的重要作用，衔接自然，故55选D。
【答案】
51.A 52.B 53.E 54.C 55.D
【知识点】
句子还原题；语篇逻辑；话题连贯
【点评】
本题考查句子还原能力，需理清文章脉络，结合上下文的话题和逻辑关系选择合适的句子，难度中等，大部分学生可通过分析前后句衔接性完成作答。
【难度系数】
0.5

五、情景交际
根据情景提示，用得体的英语完成下列对话。
56. A: ?
B: We went to the Great Wall by train.
57. A: ?
B: There are eight planets in the solar system.
58. A: Can I use your dictionary?
B: OK. .
59. A: I lost my ID card. I can't go to the library.
B: . I can help you look for it.
60. A: ?
B: I was doing my homework when you called me last night.

56. How did you go to the Great Wall
57. How many planets are there in the solar system
58. Here you are
59. Don’t worry
60. What were you doing when I called you last night

【分析】本题为英语情景交际补全对话，需结合答语内容、语境及时态确定对应语句：56题答语说明出行方式，需用一般过去时的How引导特殊疑问句询问方式；57题答语是数量，用How many引导特殊疑问句询问数量；58题是借物品同意后的常用表达；59题是安慰他人的日常用语；60题答语是过去某时刻正在做的事，需用过去进行时的特殊疑问句提问。
【解析】56. 根据答语“We went to the Great Wall by train”（表述出行方式），问句需用一般过去时的特殊疑问句，结构为How + did + 主语 + 动词原形 + 其他，故填How did you go to the Great Wall；57. 答语“There are eight planets in the solar system”是数量，用How many提问数量，结构为How many + 名词复数 + are there + 其他，故填How many planets are there in the solar system；58. 对方请求借字典，同意后递给对方的常用表达为Here you are；59. 对方因丢身份证焦虑，需用Don’t worry进行安慰；60. 答语是昨晚打电话时正在做的事，需用过去进行时的特殊疑问句，结构为What + were + 主语 + doing + 时间状语从句，故填What were you doing when I called you last night。
【答案】56. How did you go to the Great Wall；57. How many planets are there in the solar system；58. Here you are；59. Don’t worry；60. What were you doing when I called you last night
【知识点】英语情景交际、特殊疑问句、日常交际用语
【点评】本题为基础英语情景补全题，考查日常对话常用表达及不同时态的特殊疑问句运用，贴近生活实际，难度适中，适合巩固英语基础。
【难度系数】0.7