润滑油的闪点
参考答案:
润滑油加热到一定温度就开始蒸发成气体。这种气体与空气混合后遇到火焰就发生短暂的燃烧,闪火的最低温度称为润滑油的闪点。
阅读短文,判断对(√)错(×)。
Hi, I'm Fangfang. I'm eleven. I have a new room. There is a bed, a desk, a computer and two lights in it.
The desk is near the door. The computer is on the desk. The lights are on the wall. Look! What's on the bed?
It's a doll. It's yellow. I like it very much.
( ) 1. Fangfang is 12 years old.
( ) 2. There are three lights in the room.
( ) 3. The desk is near the door.
( ) 4. Fangfang's doll is green.
( ) 5. She likes the doll very much.
使用软连接牵引装置时,牵引车与被牵引车之间的距离应当大于()米小于()米。