词引力

n. 自行车，脚踏车（bicycle的名词复数）

bikes、motorcycles、bicycle
1.bicycles（名词复数，原形 bicycle）：“自行车；脚踏车”（如 “riding bicycles to work” 骑自行车上班、“mountain bicycles” 山地自行车”）；
2. bikes（名词复数，口语）：“自行车”（如 “my new bike” 我的新自行车），与 bicycles 同义，bikes 更简洁，日常口语常用；
3. motorcycles（名词复数）：“摩托车（机动车，需发动机）”（如 “riding motorcycles on the highway” 在高速公路骑摩托车），核心区别：bicycles 是 “人力驱动”，motorcycles 是 “发动机驱动”，不可混淆。

注意下面三句意思相同

【解说】He went to his office by bicycle.He went to his office on his bicycle.He rode his bicycle to his office.他骑车上班。