Jack is a twenty-year-old young man. Two years ago, when he finished middle school, he found work in a shop. Usually he works until ten o'clock in the evening. He is very tired when he gets home. After a quick supper he goes to bed and soon falls asleep. His grandma who lives downstairs is satisfied with (满意) him.
One day, on his way home, he met Mary. They were both happy. He asked the girl to his house, she agreed happily. He bought some fruit and drinks for her. And they talked about their school, teachers, classmates and their future . They talked for a long time.
“Have a look at your watch, please,” said the girl. “What time is it now?”
　　“Sorry, something is wrong with my watch,” said Jack. “Where's yours?”
　　“I left it at home.”
　　Jack thought for a moment and found a way. He began to stamp his foot on the floor, “Bang! Bang! Bang!”
　　The sound woke his grandma up. The old woman shouted downstairs, “It's twelve o'clock in the night, Jack. Why are you still jumping upstairs?”
【小题1】Jack was ________ when he finished middle school.

As everyone knows, there are many 　16　 of transportation in the world, like bicycles, buses, ships, trains and 　17　 .

If you are in big  18　like Shanghai or Beijing, maybe you get to school   19  a subway or you have to 　20　 to school because you live in a mountain village. Here I am just trying to say something about　21　 .

Ten years　22　, bicycles were very　23　in most villages.  24　 family had one or two of bicycles. Children got to school by bicycle; 　25　 rode bicycles to go shopping. Then motorcycles (摩托车)   26  to become popular. People no longer rode bicycles because motorcycles ran   27  faster.  But now, in some countries，bicycles are highly suggested

  28  the main means of transportation. They think buses, cars and motorcycles pollute(污染) the air but bicycles   29  . So, to live a low-carbon life,   30  a bike is a good way.