Bicycles were once the most important means of transportation in both China's cities and the countryside, and China was once called the "Kingdom of Bicycles". Nowadays, as traffic congestion and air pollution in cities are becoming increasingly serious, cycling is becoming popular again. Recently, Chinese entrepreneurs have invented a business model called shared bikes by combining mobile Internet technology with traditional bicycles. The emergence of shared bikes makes cycling more convenient, and people only need a mobile phone to use shared bikes at any time. To encourage people to travel by bike, many cities have built bike lanes. Nowadays, more and more Chinese people also enjoy keeping fit by cycling.
逐句译法
1. 自行车曾经是中国城乡最主要的交通工具，中国一度被称为"自行车王国"。
参考译法：Bicycles were once the most important means of transportation in both China's cities and the countryside, and China was once called the "Kingdom of Bicycles".
主干：两个分句各立一套主谓，逗号处拆成并列（主语策略：原句主语）这句中文是两个并列陈述：前半 自行车曾经是中国城乡最主要的交通工具 主干为 Bicycles + were + the most important means of transportation；后半 中国一度被称为"自行车王国" 主干为 China + was called + the Kingdom of Bicycles。两套主谓都用原句现成主语（Bicycles / China），不用补。
语法点：- 时态本句偏离全篇基调：曾经\一度 明确是历史回顾，用一般过去时 were / was，是全篇唯一该用过去时的地方。 - 单复数自行车 此处泛指自行车这类交通工具，用复数 Bicycles 作主语，谓语相应用 were。 - 用词交通工具 译 means of transportation（means 单复数同形，前面可加 the most important）；不要写成 transportations。
降级处理：用 once 表「曾经 / 一度」，被动接称号「曾经」「一度」都译成副词 once，分别放进两个分句（were once / was once called）。后半 被称为 是天然被动，译 was called / was known as，称号 the Kingdom of Bicycles 直接接在后面。两分句用 and 连接即可，因为它们语义平行、长度相当。
2. 如今，随着城市交通拥堵和空气污染日益严重，骑自行车又开始流行起来。
参考译法：Nowadays, as traffic congestion and air pollution in cities are becoming increasingly serious, cycling is becoming popular again.
主干：动名词 cycling 作主语承载「骑自行车」（主语策略：补主语）中文末句 骑自行车又开始流行起来 的「骑自行车」是动作，英文把它提为动名词 Cycling 作主语，主谓为 Cycling + is becoming / has become popular again。前面 随着…日益严重 是背景，不进主干。
语法点：- 时态回指全篇基调用一般现在时；为体现 日益严重 的渐变可用现在进行 are getting more serious，又开始流行起来 可用 is becoming popular again 或 has become popular again。 - 主谓一致动名词 Cycling 作主语视为单数，谓语用 is becoming / has become，不要写成 are。 - 用词交通拥堵 译 traffic congestion（congestion 不可数）；日益严重 译 increasingly serious 或 more and more serious。
降级处理：「随着…」降级成 As 状语从句随着城市交通拥堵和空气污染日益严重 降级成原因 / 伴随状语从句：As traffic congestion and air pollution in cities are getting increasingly serious，挂在主句前；主句只留 cycling is becoming popular again。这样背景与主句层次分明，不平铺。
参考译法：Recently, Chinese entrepreneurs have invented a business model called shared bikes by combining mobile Internet technology with traditional bicycles.
主干：「企业家」作主语，「发明」作主谓（主语策略：原句主语）本句两个动词「结合」「发明」中，发明了一种…商业模式 是结果与重点，定为主干：Chinese entrepreneurs + have invented / invented + a business model。主语用原句现成的 中国企业家。
语法点：- 时态近来 提示动作影响延续至今，宜用现在完成时 have invented；若理解为过去某时点的发明用一般过去时 invented 亦可，但全文以现在时叙现状，完成时更连贯。 - 介词搭配「把A与B结合」固定搭配 combine A with B，不是 combine A and B、更不是 combine A to B。 - 单复数与冠词一种…商业模式 用单数加不定冠词 a business model；传统自行车 泛指用复数 traditional bicycles。
降级处理：「结合」降级成 by V-ing，「称为」降级成定语将移动互联网技术与传统自行车结合在一起 是发明的手段，降级成方式状语 by combining mobile Internet technology with traditional bicycles；称为共享单车(shared bikes)的 是修饰商业模式的定语，降级成过去分词 called shared bikes 后置修饰 a business model。主干外两个成分各归其位，不平铺。
4. 共享单车的出现使骑车出行更加方便，人们仅需一部手机就可以随时使用共享单车。
参考译法：The emergence of shared bikes makes cycling more convenient, and people only need a mobile phone to use shared bikes at any time.
主干：前半 make 句型，后半 people 作主语（主语策略：原句主语）逗号两边各立主谓。前半 共享单车的出现使骑车出行更加方便 用 make sb/sth + 形容词句型：The emergence of shared bikes + makes + cycling + more convenient。后半 人们仅需一部手机就可以随时使用共享单车 用原句主语 People：People + only need + a mobile phone…
语法点：- 时态回指全篇基调用一般现在时：makes、need、can use，叙述当前普遍事实。 - 主谓一致前半主语 The emergence（单数）配 makes 加 s；后半主语 People（复数）配 need 不加 s、can use。两个谓语别用错形式。 - 单复数与冠词一部手机 用单数加冠词 a mobile phone；共享单车 泛指仍用复数 shared bikes，与全篇统一。
降级处理：两件事拆成两句，「仅需…就」用 only need前后两个分句各自完整、各有主语（出现 / 人们），拆成两个独立句更清楚。后半 仅需一部手机就可以随时使用 中，「仅需…就可以」用 only need… to use / and can use，「随时」译 at any time 或 whenever they want 作状语。
5. 为了鼓励人们骑车出行，很多城市修建了自行车道。
参考译法：To encourage people to travel by bike, many cities have built bike lanes.
主干：「很多城市」作主语，「修建」作谓语（主语策略：原句主语）主干取 很多城市修建了自行车道：Many cities + have built / have constructed + bike lanes。主语用原句现成的「很多城市」，目的状语不进主干。
语法点：- 时态修建了 已完成且结果（车道）至今存在，用现在完成时 have built 最贴；用一般过去时 built 也通，但完成时与全篇叙现状更连贯。 - 单复数很多城市 用复数 many cities；自行车道 不止一条用复数 bike lanes / bicycle lanes。 - 搭配「鼓励某人做某事」固定 encourage sb to do sth，to 后用动词原形 cycle 或 travel by bike。
降级处理：「为了…」降级成 To do 目的状语为了鼓励人们骑车出行 是目的，降级成不定式目的状语 To encourage people to cycle / to travel by bike，前置于句首。主句保持 many cities have built bike lanes，结构清爽。
6. 现在，越来越多的中国人也喜欢通过骑车健身。
参考译法：Nowadays, more and more Chinese people also enjoy keeping fit by cycling.
主干：「越来越多的中国人」作主语，「喜欢」作谓语（主语策略：原句主语）主干为 越来越多的中国人也喜欢：More and more Chinese people + like / enjoy + 宾语。主语用原句的「中国人」，谓语取核心动词「喜欢」。
语法点：- 时态现在 提示当前事实，回指全篇基调用一般现在时 like / enjoy。 - 主谓一致主语 More and more Chinese people 是复数，谓语 like / enjoy 不加 s。 - 搭配与词形enjoy / like doing：enjoy keeping fit、by cycling 用动名词；健身 译 keep fit / stay healthy / exercise 均可。
降级处理：「通过骑车健身」降级成动名词宾语 + 方式状语通过骑车健身 含「健身」与「骑车」两个动作：「健身」是目的、「骑车」是方式。可处理为 enjoy keeping fit by cycling（健身作动名词宾语，骑车作 by doing 方式状语），或 like to exercise by riding bikes。主干外成分按手段 / 目的归位，不平铺。
词汇与译名提示
自行车王国自行车王国 是带引号的称号式文化表达，宜意译为 the Kingdom of Bicycles（首字母大写、保留引号或不加引号均可），全篇若再次出现只用这一种译法。它是「称号」，所以前面常配 be called / be known as。
共享单车原文已给出官方英文 共享单车(shared bikes)，全篇统一就用 shared bikes（复数泛指这一类车），不要一会儿 shared bicycle、一会儿 bike-sharing 混用；指「共享单车这种商业模式」时可说 a business model called shared bikes。
移动互联网技术移动互联网技术 统一译为 mobile Internet technology（Internet 首字母大写、technology 不可数不加 s），全篇保持一致。