润滑系有哪些功用?
参考答案:向摩擦表面提供干净的润滑油,以减少摩擦损失和零件的磨损;通过润滑油的循环,还可冷却和净化摩擦表面;润滑油膜附着在零件表面,能防止氧化和腐蚀。
—Now the weight. Only 115. You’d better put on a few pounds.
—Well, actually, I ________ like a horse.
A.ate
B.was eating
C.have been eating
D.will eat
述哪一种情况可不拍摄颅脑CT的骨窗 ()
A.蝶鞍
B.脑萎缩
C.颅脑外伤
D.颅骨病变
E.内听道病变