完形填空。 Do you like to go camping (野营)? Do you know how to start a fire? If you don't know how to start a fire, you 1 your food, and can't sit by the side of a fire, and can't keep yourselves 2 . Long, long ago people 3 how to start fires. They probably started fires from lightning (闪电). But they had to 4 the lightning fire burning, for there was 5 to start it 6 . Later people learned how to start fires. They 7 out hitting two pieces of stone (石头) together could make a spark (火光).The spark could set 8 on fire (set…on fire 使…… 燃烧). They could start this kind of fire again if it went out (熄火). Then people also learned to make a fire by rubbing (摩擦) two sticks together. They made a hole (洞) on a large stick and put the 9 stick into the hole. And then they turned the stick again and again. 10 a few minutes they started a fire. About two hundred years 11 , people began to 12 matches (火柴). One early match looked 13 the match we use today. The match gave people a 14 way to start fires. Today people are 15 finding new ways to start fires. One of the new ways to start a fire is to use an electric fire starter (电子打火器). Now you can 16 matches and electric fire starter at 17 . Of course an electric fire starter is more expensive than 18 , 19 it is useful. After people learned to make fires, their lives became 20 . (     )1. A. can cook (     )2. A. quiet (     )3. A. have known (     )4. A. ask (     )5. A. no way (     )6. A. only (     )7. A. took (     )8. A. dry paper (     )9. A. larger (     )10. A. After (     )11. A. before (     )12. A. invented (     )13. A. up (     )14. A. quick and easy (     )15. A. always (     )16. A. sell (     )17. A. home (     )18. A. a match (     )19. A. so (     )20. A. harder and harder B. can eat B. full B. knew B. keep B. no idea B. again B. found B. wet leaves B. large B. Before B. ago B. do B. different B. slow and difficult B. already B. buy B. factories B. a box of match B. and B. easier and easier C. can’t cook C. hot C. haven’t known C. let C. a way C. more C. looked C. wet paper C. smaller C. When C. later C. make C. the same C. new and interesting C. even C. see C. shops C. a box of matches C. but C. longer and longer D. can’t eat D. warm D. didn’t know D. make D. an idea D. either D. heard D. dry leaves D. smallest D. For D. after D. used D. like D. important and clever D. still D. find D. towns D. a box matches D. because D. happier and happier