单词拼写：根据英文释义和例句，完成下列单词的拼写，每个单词的第一个字母已给出。

　　l________ in a lucky matter

　　He is happy that he has passed the exam ________.

---I feel really tired.

---___________________

　 A. Lucky you!　　　　　　　　　　　　　　　 C. You’d better work harder.

　 C. Congratulation!　　　　　　　　　　　　　　 D. Why not go and have a reat?

The bicycle is one of the simplest yet most useful inventions in the world. What is most surprising is that it was not ___1__ earlier, although the great inventor Leonardo Da Vinci had drawn pictures for bicycles and also for flying machines and some other things. Those things were not produced___2___ long after he died.

　　A person riding a bicycle uses ___3___ energy to make the bicycle move, and there is no pollution at all when you are riding. Even so, in developed ____4___, most people don’t travel to work by bicycle. It is not because the bicycles are expensive or people feel___5____ if they ride to work. It’s because __6___ cars on the roads becomes larger. It certainly becomes ___7___ to ride a bicycle. As a result, more people put their bicycles away and go to work ___8___ their cars cars, and in this way, the situation is made more serious.___9___ the best way to make riding safer and more popular is to create paths (开设通道) only for bicycles, and to make ___10___ so difficult and expensive for drivers to take their cars into the city that they will go back to use their bicycles.