例句：
Draughts help to circulate air.
通風(fēng)有助于循環(huán)空氣。
Leave a gap at the top and bottom so air can circulate.
在頂部和底部各留一點(diǎn)空隙，這樣空氣就可以流通了。
Rumours began to circulate about his financial problems.
有關(guān)他財(cái)務(wù)困難的謠言開(kāi)始流傳開(kāi)來(lái)。