以下关于碾压混凝土的说法，不正确的是( )。
A．碾压混凝土中往往需要加入缓凝剂、减水剂或引气剂
B．碾压混凝土常用于道路、机场和水利工程
C．碾压混凝土由级配良好的集料、较低水泥用量和水用量、较多混凝土材料制成
D．碾压混凝土的缺点在于成本高
参考答案：D
解析： 碾压混凝土是由级配良好的集料、较低水泥用量和水用量、较多混合材料(往往加入适当的缓凝剂、减水剂或引气剂)制成超干硬性混凝土拌合物，经振动碾压等工艺达到高密度、高强度的混凝土。它是道路工程、机场工程和水利工程中性能好、成本低的新型混凝土材料。
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| It was a cold winter's night when I stopped for gas on my way home from work. I was tired and had a slight 1 . I worked in a 2 doctor's office and this was one of those days when the unexpected happened, making the schedule run 3 than usual. It seemed I was going to be late 4 home and my husband, being the 5 person, would be ready to pronounce me late once again. Maybe 6 I hurried, I could still make it home. I was heading inside to 7 for my gas when I noticed an older couple at the counter. I heard them asking for 8 to the local hospital. It was the same hospital that I had just 9 a few minutes ago. The young man at the counter was trying to be 10 in explaining how to get there, with two other people making 11 . One of them was 12 trying to give them a whole different route back. It was then that I walked over to the couple and said, "Would you like to follow me to the 13 ?" A look of 14 crossed the woman's face. "I'm going right by there," I said, which wasn't a(an) 15 since I had just made up my mind to do 16 that. I got in my car and began the journey back. I was trying to watch to be sure they were right 17 me. It took only fifteen minutes to get there as rush hour traffic was beginning to 18 . I felt better than I had all day and my headache was nearly gone. Later, as I arrived home, my husband 19 , "So you aren't ever late any more." I said, "Sometimes it's 20 to be late." | |||
| ( )1. A. break ( )2. A. foreign ( )3. A. earlier ( )4. A. getting ( )5. A. tough ( )6. A. as ( )7. A. pay ( )8. A. opinions ( )9. A. reached ( )10. A. skilled ( )11. A. comments ( )12. A. only ( )13. A. station ( )14. A. panic ( )15. A. duty ( )16. A. partly ( )17. A. across ( )18. A. go up ( )19. A. teased ( )20. A. possible | B. fever B. common B. later B. cooking B. punctual B. since B. change B. trouble B. visited B. helpful B. promises B. still B. office B. relief B. fact B. properly B. before B. die down B. shouted B. special | C. cold C. busy C. easier C. calling C. generous C. while C. wait C. directions C. called C. experienced C. jokes C. even C. hospital C. sadness C. reason C. exactly C. beside C. speed up C. burst C. good | D. headache D. noisy D. simpler D. working D. careful D. if D. search D. money D. left D. active D. offers D. ever D. hotel D. peace D. lie D. perfectly D. behind D. turn down D. laughed D. safe |