Example: you need to get to the nearest underground station, but you don't know the way?
1 you feel hot and want to open the window, but there are other people in the room?
2 you need to make an urgent telephone call, but you don't have your mobile phone with you?
3 people at the table next to yours talk very loudly and you can't hear what your friend is saying to you?
4 you want to express your gratitude to someone who helped you a lot?
5 someone tells you that he's grateful for your help and consideration?