I. 1. are sold out

   2. play jokes

   3. in line

   4. show up

   5. gives me a lift

   6. end up

II. 1-5 EDCBA

III. 1. had built

     2. had affected

     3. had borrowed

     4. had had

     5. had stopped

     6. had lived; came

     7. found; had disappeared

IV. 1. forgot doing

     2. by the end of the year

     3. ran away from home

     4. hundreds of customers

     5. wake up

     6. is about to / is going to

V. One possible version:

An Unexpected Experience

Today I went to the National Museum to see an exhibition. But some bad things happened to me. When I arrived there I found that I had left my mobile phone at home. It took me more than an hour to get there and I waited in line for about two hours to buy tickets. I had no choice but to see the exhibition. Things on show were so wonderful that I forgot the time. I always felt it was a shame that I couldn’t take photos with my mobile phone. After the exhibition, I hurried to the bus stop. Unluckily, the last bus had left fifteen minutes before and I had to walk home. What was worse, by the time I got home, I realized that I couldn’t find my keys. What an unexpected experience I had today!