在测量电动势之前如何进行校准化操作？
参考答案：
根据室温按公式ES=1.0183-4.06×10-5（t-20），计算标准电池在该室温下的ES。
1）将“测量选择”旋钮置于“外标”。
2）将已知电动势的标准电池按“+”“—”极性与“外标插孔”连接。
3）调节“100-10-4”五个旋钮和“补偿”旋钮，使“电位指示”显示的数值与外标电池数值相同。
4）待“检零指示”数值稳定后，调节调零旋钮，使“检零指示”显示为“0000”。
| 完形填空。 | ||||
| One night I was driving from Harrisburg to Lewisburg, a distance of eighty miles. I was late so I drove very 1 . Several times I got stuck behind a slow-moving truck on a narrow road, and I was shouting and 2 the steering wheel（方向盘）with impatience. At one point along an open highway , I came to a crossroads with a traffic light. I was alone on the road, but as I got 3 the light, it turned red and I stopped. I looked left, right and behind me. Nothing. Not a car, no 4 of headlights, but there I sat, waiting for the light to change, the only human being for at least a mile in any 5 . I started wondering why I refused to run the red light. There was obviously no policeman around, and it certainly would not have been 6 in going through it. Later that night, after I had climbed into bed, the question of why I stopped for that light 7 back to me. I did so because it's part of a contract (协议) we all have with each other. It's not only the law, but an agreement we have, and we trust each other to 8 it. It's 9 that we ever trust each other to do the right things. It's a good thing because the whole structure of our society depends on trust. This whole thing we have going for us would fall apart if we didn't trust each other most of the time. We do 10 we say we'll do; and we pay when we say we'll pay. We trust each other in these matters, and when we don't do what we've 11 , others will be angry or disappointed with us because we violate(亵渎) the 12 they have in us. I was so proud of myself for stopping for the red light that night! | ||||
|