1.When I looked at my watch, I realised that I was late for a meeting. 

2.When I looked at my watch, I realised that I had been writing a letter for 3 hours. 

3.When I looked at my watch, I realised that Tom missed the train. 

4.When I looked at my watch, I realised that they were going to school. 

1.Tom was upset because he forgot his passport. 

2 . Tom was upset because he had been looking for his passport for too long

3.Tom was upset because he hadn't arrived to the airport in time. 

4.Tom was upset because he had been driving for nothing.