有关润滑油的作用说法错误的是（）。
A.密封
B.冷却
C.提高抗爆性
D.润滑
参考答案：C
排一排．
（1）4.504.0540.50.455.400.54
______＜______＜______＜______＜______＜______；
（2）1千米27000dm2102公顷
______＞______＞______．
— _____ all the students known that our class will visit the museum this weekend?
—Yes, every student _____ about it. [ ]
A. Has; tells
B. Has; told
C. Have; was told
D. Have; were told
