润滑脂在摩擦面上保持性良好,可以充满间隙,因之有()作用。
A.润滑
B.冷却
C.洗涤
D.密封
参考答案:D
We have every reason to believe that __________ 2012 London Olympics will be ________ great success.
A.a; /
B.the; /
C.the; a
D.a; a
劳动就业的概念表述?