Nowadays, just about everyone has a mobile phone. This wonderful invention helps people to stay in touch with others at any time of day and night and no (1) ... where they are. It has brought people closer and it must certainly have saved many lives by enabling immediate contact with the emergency services. It also, on the other (2) ..., has its disadvantages. Perhaps the (3) ... obvious of them is the sound of people talking loudly on their phone on public transport, unaware of (4) ... much they are disturbing other travellers.