1 Why are your clothes dirty? Because I have been working in the garden all morning.
2 Have you ever met a pop star?
3 What time does train leave?
4 Does your mother cool well?
5 I have seen the dentist today.
6 How long have you been studying English?
7 We haven't seen Tina for ages.
8 My brother always throws all things around the house, this annoys me very much.
9 I am playing a computer game at the moment.
10 We have known the Smiths for 5 years already.