bouts
n. 发作;来回一次(bout 的复数)
例句
He suffered occasional bouts of depression.
他有时会犯抑郁症。
《牛津词典》
There were inevitable bouts of homesickness.
难免会生出一阵阵思乡之情。
《柯林斯英汉双解大词典》
Unlike the song sparrow, which repeats one of its several song types in bouts before switching to another, the warbler continuously composes much longer and more variable songs without repetition.
北美歌雀在切换到另一种类型之前,会一声一声地重复其中的一种,与之不同的是,北美歌雀会连续地创作更长的、更多变的歌曲,而不会重复。