1.循环，周期
2.自行车，摩托车
3.整套，整个系列（如机器的运转）
不及物动词：
1.骑自行[摩托]车，骑自行车 词形变化
- 名称 cycler
- 时态 cycled，cycling，cycles
- an interval during which a recurring sequence of events occurs
- ride a bicycle
- the unit of frequency; one hertz has a periodic interval of one second
- ride a motorcycle
- pass through a cycle
- cause to go through a recurring sequence
- recur in repeating sequences
- a series of poems or songs on the same theme
- a wheeled vehicle that has two wheels and is moved by foot pedals
- a single complete execution of a periodically repeated phenomenon
- a periodically repeated sequence of events