1.Past Indefinite Tense, Present Perfect, Past Continuous  or Present Perfect Continuous?
Little Mary came in. She … (eat) an ice-cream. 
I dropped my bag when I … (run) for a bus. 
I … (know) him for years.
She … (work) here for five years. 
I … (return) home yesterday. 

Привет! Я думаю так:1) Little Mary came in. She was eating an ice-cream.2) I dropped my bag when I ran for a bus.3) I have known him for years.4) She has been working here for five years.5) I returned home yesterday.