aff and on的用法和樣例：
例句
- He had been work here,on and off,for two years.
他在這兒斷斷續續工作了兩年。 - I began to write intermittently and spasmodically.
我開始斷斷續續地寫了起來。 - He had to work all day and every day to earn a living.
為了謀生，他只有永不間歇地工作。 - A numbers station is a government operated radio station broadcasting intermittently on the short-band frequencies.
電台是政府操作的無線電發射站，間歇地發射短波頻率。
