Complete the sentences with the present perfect continuous form of the

Complete the sentences with the present perfect continuous form of the verbs in brackets and explain why this tense is used in each setence.
1 - Why are you so late? I ... (stand) here for hours!
- I ... (try) to remember the Russian name of street where you live.
2 - How long is it since you started learning Russian?
- I ... (learn) it since you i came to Russia.
3 - You look happy.
- Yes, i ... (talk) with my parents in Boston for half an hour.
4 - Why are you so wet?
- I ... (wait) for a bus for two hours and i left my umbrella at home.
5 - Could you help me, please. i ... (look) for my passport for a long time and i can't find it.