根据句子意思，用所给单词的适当形式填空。未提供单词的根据上下文填入适当的词。

England nobody under eighteen years old is allowed  (drink) in a bar. Mr Thompson often went to  bar near his house. But he never took his son, Tom,  he was too young. Then when Tom had his  (eighteen) birthday, Mr. Thompson took him to his usual bar  the first time. They drank for an hour. Tom drank a bit. Then Mr "Now, Tom, I want (teach) you a (use) lesson.
    do you know when you've had enough? Well I'll tell you. Do you see (that) two lights at the end of the bar? When they seem (become) four, you've had enough and should go home."

"But, Dad," said Tom, "I can only see one light at the end of the bar."