n. 循环动作；圈数；周期（cycle的复数）

n an interval during which a recurring sequence of events occurs

n a series of poems or songs on the same theme

n a periodically repeated sequence of events

n the unit of frequency; one hertz has a periodic interval of one second

n a single complete execution of a periodically repeated phenomenon

n a wheeled vehicle that has two wheels and is moved by foot pedals

v cause to go through a recurring sequence

v pass through a cycle

v ride a motorcycle

v ride a bicycle

v recur in repeating sequences