问题
单项选择题
轴承合金有锡锑轴承合金和铅锑轴承合金两大类。锡锑轴承合金摩擦系数小,抗胶合性能良好,对油的吸附性强,耐腐蚀性好,易跑合,是优良的轴承衬材料,常用于高速、重载的轴承上。但它价格较贵且机械强度较差。此轴承合金在(),开始软化,因此在设计、运行中常将温度控制在比此温度低30~40℃。
A.80℃
B.llO℃
C.150℃
D.200℃
答案
参考答案:B
轴承合金有锡锑轴承合金和铅锑轴承合金两大类。锡锑轴承合金摩擦系数小,抗胶合性能良好,对油的吸附性强,耐腐蚀性好,易跑合,是优良的轴承衬材料,常用于高速、重载的轴承上。但它价格较贵且机械强度较差。此轴承合金在(),开始软化,因此在设计、运行中常将温度控制在比此温度低30~40℃。
A.80℃
B.llO℃
C.150℃
D.200℃
参考答案:B
完型填空。 | |||
That day was like any other day in his life. After school Michael walked past the shop in the street corner. He stopped to 1 the front row of shoes, and he felt sorry for himself. He 2 wanted to have a pair for his birthday. He walked away sadly and thought of what to tell his mother. He knew she would give him 3 if she could. But he also knew very well she had 4 money. He decided not to go home 5 as he looked worried and his mother would notice it. So he went to the park and sat down on the grass. Then he saw a boy in a wheel chair. He noticed that the boy moved the wheels with his hands. Michael looked at him carefully and was 6 to see that the boy had no feet. He looked 7 at his own feet. "It is 8 better to be without shoes than 9 feet." he thought. There was no reason for him to 10 so sorry and sad. He went away and smiled, thinking he was more lucky in his life. | |||
( )1. A. see ( )2. A. gladly ( )3. A. something ( )4. A. little ( )5. A. at once ( )6. A. pleased ( )7. A. up ( )8. A. much ( )9. A. out of ( )10. A. look | B. look at B. nearly B. what B. a little B. then B. excited B. through B. quite B. with B. feel | C. hear C. really C. nothing C. much C. just now C. surprised C. out C. very C. without C. appear | D. notice D. quickly D. anything D. lots of D. at all D. interested D. down D. less D. having no D. seem |