20小题。
Bob and I live in the same building.His room is on the tenth floor,but mine is on the ninth floor.He is kind but careless,and sometimes gets into trouble.
Last Friday afternoon,the young man went to a wild island to spend his holiday with his friends.They swam in the river,went fishing,played the guitar.They had a good time.Three days later,they decided to come back to the bank.Unfortunately,their boat hit a rock and soon went down.They were all in danger.With a villager's help,all of them were out of danger.They didn't come back until midnight.The young man was too hungry and quite tired.So he wished to get home as soon as possible.But the lift didn't work.He had to walk upstairs.He stopped by my door and took out a key.Of course,he could not open the door.He tried it again and again,but failed.He became angry and shouted,"I'll cut you down with a knife!"
The noise woke me up and I opened the door.I understood at once what was happening and said,"You are trying to open a wrong door,Bob."
"Sorry,I can't agree with you,Mike!" he shouted,"It's my room.You have entered it by mistake!"
16. On which floor is Bob’s room?
17. Did they have a good time on the island?
18. How long did they stay on the island?
19. How did Bob go upstairs?
20. Who opened the door by mistake, Bob or Mike?