正确的操作能保证实验顺利进行。请填写下列有关实验操作中的空格: (1)用酒精灯给

题型:填空题

问题:

正确的操作能保证实验顺利进行。请填写下列有关实验操作中的空格:    

(1)用酒精灯给物质加热时,要用酒精灯火焰的       ;    

(2)玻璃仪器内壁洗干净的标准是                                  

(3)实验中,若不小心将酒精灯碰翻在桌上,桌上洒落的酒精燃烧起来,最简捷有效的扑灭方法是              

考点:加热器皿—酒精灯安全措施和生活经验仪器的洗涤
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词汇运用(10分)从方框中选择适当选项,并用其正确形式填入短文后相应题号的横线上,使短文通顺、完整,选项中有两项多余
dirty    with    have    always    time    they
large    want    speak    lesson    first    drop
After a quick breakfast, I went into the lecture hall in a hurry. A famous teacher was 小题1:  to the students. He was holding up a $100 bill. Then he said to the three hundred students, "Who would like this $100 bill?" The students put up小题2:hands at once. Then he said,"I am going to give this $100 bill to one of you,but 小题3: , let me do this." He made the bili into a ball. Then he said, "Who 小题4: it now?" The hands went back into the air. "Well," he said,,What if I do this?" and he小题5:it on the floor and stepped on it. He picked up the 小题6:bill and said,"Who still wants it?" Hands went back again into the air.
"My friends," he said,"you have learned a valuable(有价值的) 小题7:today. No matter what I did to the $100 bill! Many小题8: in our life, we are dropped and stepped on. We feel as if we are worth nothing. But remember, no matter what小题9:happened to you, you will never lose your value.You are 小题10:valuable to those people who love you. Your value doesn’t come from what you do or whom you know, hut who you are."
题型:填空题
y=
2x-1
+3
1-2x
-2
,则代数式xy的值为(  )
A.4B.
1
4
C.-4D.-
1
4
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下列各组元素中,第一电离能依次减小的是

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离心泵易产生气蚀现象,所以在开泵前应排净泵内气体并关闭入口阀门。

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长沙市公共建筑应当严格执行室内空调温度控制的有关规定,冬季室内空调温度设置标准是不得高于多少摄氏度?

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