枕养护中常用防腐材料有哪些？
参考答案：
桥枕养护中常用防腐材料有二种：
⑴氟化钠--为能溶于水的白色粉末或晶体，饱和溶液的浓度约为４～4.5％，是一种强烈的防腐剂和毒药，靠木材中水份渗入扩散到木材内部去，浓度0.6％即能杀菌，但也能引起人的皮肤炎或溃伤，所以应妥善保管、专人负责管理。
⑵煤焦油--为深褐色的粘稠液体，用棍片挑起，能延挂成线，引续不断，不溶入汽油或煤油，有一种很浓的特种味道，涂在木料上长时间不易干燥，氟化钠煤焦油浆膏是用氟化钠和煤焦油大致按1：1的重量混合制成，调制时将煤焦油加热到35--40℃，最后把氟化钠倒入搅拌均匀即可，夏天可不加热，冬天如确实过稠，可在加热的煤焦油中加入少量柴油等稀释之。由于氟化钠易沉淀，使用时应经常搅拌。
（材料各占３．５分，共计７分，拌合要注占３分，错误、遗漏者扣２分。共计１０分）
| 完形填空。 | |||
| The True Story of Treasure Island It was always thought that Treasure Island was the product of Robert Louis Stevenson's imagination. 1 , recent research has found the true story of this exciting work. Stevenson, a Scotsman, had lived 2 for many years. In 1881 he returned to Scotland for a 3 . With him were his American wife and his son 4 . Each morning Stevenson would take them out for a long 5 over the hills. They had been 6 this for several days before the weather suddenly took a turn fro the worse. Kept indoors by the heavy rain, Lloyd felt the days 7 . To keep the boy happy, Robert asked the boy to do some 8 . One morning, the boy came to Robert with a beautiful map of an island. Robert 9 that the boy had drawn a large cross in the middle of 10 ."What is that?" he asked. " That's the 11 treasure ,"said the boy. Robert suddenly 12 something of an adventure story in the boy's 13 .While the rain was pouring, Robert sat down by the fire to write a story. He would make the 14 a twelve-year-old boy, just like Lloyd. But who would be the pirate (海盗) ? Robert had a good friend named Henley, who walked around with the 15 of a wooden leg. Robert had always wanted to 16 such a man in a story . 17 Long John Silver, the pirate with a wooden leg, was 18 . So, thanks to a 19 September in Scotland, a friend with a wooden leg, and the imagination of a twelve-year-old boy, we have one of the greatest 20 stories in the English language. | |||
| ( )1. A. However ( )2. A. alone ( )3. A. meeting ( )4. A. Lloyd ( )5. A. talk ( )6. A. attempting ( )7. A. quiet ( )8. A. cleaning ( )9. A doubted ( )10. A the sea ( )11. A. forgotten ( )12. A. saw ( )13. A. book ( )14. A. star ( )15. A. help ( )16. A. praise ( )17. A. Yet ( )18. A. read ( )19. A. rainy ( )20. A. news | B. Therefore B. next door B. story B. Robert B. rest B. missing B. dull B. writing B. noticed B. the house B. buried B. drew B. reply B. hero B. problem B. produce B. Also B. born B. sunny B. love | C. Besides C. at home C. holiday C. Henley C. walk C. planning C. busy C. drawing C. decided C. Scotland C. discovered C. made C. picture C. writer C. use C. include C. But C. hired C. cool C. real-life | D. Finally D. abroad D. job D. John D. game D. enjoying D. cold D. exercising D. recognized D. the island D. unexpected D. learned D. mind D. child D. bottom D. accept D. Thus D. written D. windy D. adventure |