问题 问答题 简答题

使用冷却液时有哪些注意事项?

答案

参考答案:

①冷却润滑液要有一定的压力,以便连续不断地直接喷射到砂轮与工件接触区,这样才能及时带走磨削区域的热量,在砂轮和工件之间产生润滑作用,并把磨屑和碎磨粒冲洗干净;

②冷却液要充足,并应均匀喷射到整个砂轮宽度上;

③冷却液应保持清洁。在冷却系统的回水口和冷却泵的吸水口都要设过滤网,以免冷却液中混有磨屑、碎磨粒和尘埃等杂物,而造成砂轮堵塞弄脏和变质的冷却液要及时更换,并彻底清洗机床和水箱。

阅读理解

阅读理解。

     On day, Allan and his friend Henry went swimming in a river. It was very hot. How happy they were in

the river! After they got out of the water, they played games in the sun for a while.

     On their way back, Henry saw some flowers. He liked flowers very much and ran into the green field to

look at them. Now Allan was walking by himself. Then he heard Henry calling out, "A snake! Help!........."

"What's wrong with you?" asked Allan. "A snake bit (咬) me in the leg. Come here!" Allan ran over and saw

a small red wound (伤口) on Henry's leg. "The snake was in the grass. I didn't see it." "Sit down quickly!"

Allan told Henry. Allan put his mouth at the little red would and began to suck (吸) at it. In this way he

saved (挽救) Henry's life. "Oh,Allan, it's very kind of you to help me."

      "That's all right. We are friends and we must always help each other."

1. It was            when Allan and Henry went out. [ ]

A. hot

B. cold

C. raining

D. wet

2. After swimming, they played in the sun           . [ ]

A. the whole morning

B. for 2 hours

C. long

D. for a while

3. On the way home, _____ got something wrong with his _____.[ ]

A. Allan, leg

B. Allan, head

C. Henry, leg

D. Henry, head

4. Henry and Allan are _____. [ ]

A. workers

B. good friends

C. brothers

D. farmers

5. Which of the following is true? [ ]

A. Henry went to look at the flowers with Allan

B. Allan saved Henry's life

C. Allan saw the snakes

D. They ran to the hospital

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