液压元件安装前要用()清洗,自制的重要元件应进行密封和耐压试验。
A.菜油
B.机油
C.煤油
D.汽油
参考答案:C
改错。
( ) 1. Would you like some pops? _______________
A B C
( ) 2. What colour are your hair? _______________
( ) 3. I hear with my eyes. _______________
( ) 4. Show I your left hand. _______________
( ) 5. I has small ears. _______________
下面哪个属于第三方物流主要的运行模块()
A.加工模块
B.装配模块
C.车辆调度模块
D.信息模块