问题
单项选择题
晶闸管阳阴极间加上正向电压而控制极不加电压，此时晶闸管处于（）状态。
A.正向阻断
B.反向阻断
C.反向导通
D.正向导通
答案
参考答案：A
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晶闸管阳阴极间加上正向电压而控制极不加电压，此时晶闸管处于（）状态。
A.正向阻断
B.反向阻断
C.反向导通
D.正向导通
参考答案：A
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| Last week I went to a supermarket. After I 1 the bill and was passing through the door, the alarm suddenly started to ring. Suddenly, a young guard ran toward me and ordered me to 2 him. I felt so upset and 3 . He took me to a small room, but I was 4 frightened that I stopped at the door. Finding me 5 to enter the room, he shouted that I had to go into the room. He closed the door. I thought he was going to hurt me. Suddenly, a 6 voice said in my ear: "Take out the things you've stolen!" "I stole nothing." I said. "Do as I tell you. If we find them, you'll be in trouble." "There is nothing." I answered. "I didn't take anything." I said, taking everything out of my pockets and bag. 7 this point, a guard came in and asked a salesgirl to 8 me. 9 , they found nothing. But they didn't believe that I hadn't stolen anything. So the young guard ordered me to pass through the door alarm again. I was 10 when it rang again. I felt 11 and burst into tears. I didn't know how to prove 12 I was innocent(清白的). They made me go into the small room again. "Take out the stolen things quickly, 13 we will dial 110." They said. "OK, call the police. I' m not afraid." I said 14 . Suddenly, they 15 their tone. After a while, a salesgirl asked me to raise my feet. I did 16 she had told me. There was a label (标签) on the bottom of my shoe. That was it! That was the 17 thing that had brought me such great trouble. But it 18 my innocence. After that, they 19 to me in the small room, But they should have apologized 20 , shouldn't they? A lot of people were there when I was taken away. What did they think of me? | ||||
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