四辊支承辊采用唇形密封圈,唇的方向朝外主要目的是()
A.防止油脂泄漏
B.防止氧化铁皮及水的进入
C.装配方便
D.便于散热
参考答案:B
—What time do you usually get up?
—____________. [ ]
A. I usually get up in the morning.
B. I usually get up six forty.
C. I usually get up at six o'clock.
D. I usually get up at six forty o'clock.
血液检测试剂进货验收与放行记录表中附件应包括哪些?