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. a single complete execution of a periodically repeated phenomenon
n. 周期, 循环, 自行车, 一段时间, 整套
vi. 循环, 轮转, 骑自行车
vt. 使循环, 使轮转
[计] 环路; 周期; 循环