I wonder whether Mike is getting annoyed with me. I had promised to help him       his maths in the library this afternoon. 
just as I was about to start out, Uncle John,    
  had just come back from abroad, came to see me. John has always been a good friend as well    
a good uncle. He used to come to see me when I was young, but I had not seen him for ages.     had a good chat and had a very nice time together. I tried to call Mike and tell him about the delay, but wasn’t able
reach him since his mobile phone was powered off. When I got to the library, he was nowhere to be seen. He was likely to be very upset, since I should have met him there. I think I’d better apologize to him tomorrow    
   not keeping the appointment. I’d rather tell him the truth than make    
  excuse.