气门摇臂的润滑方式是（）。
A、压力
B、飞溅
C、混合
D、压力加飞溅
参考答案：A
空气的体积质量是1.239×10-3g/cm3 ，用小数把它表示出来为（ ）g/cm3
-Smoking is bad for your health.
-Yes, I know. But I simply can't __________.[ ]
A. give it up
B. give it in
C. give it out
D. give it away
