had been 加過去分詞是什麼時態

At that time I had been job-hunting for six months.

那時我找工作已經找了六個月了。

Particles of glass had been introduced into the baby food.

這種嬰兒食品中被摻進了玻璃碎屑。

At that time they had been courting for several years.

當時他們已經談了好幾年的戀愛了。

He had been abroad many times.

他曾多次出國。

It was the third day running that the train had been late.

列車已經連續三天晚點了。