主页
学科
搜索
账户
常见问题
当前学科:电气工程公共基础
题目:
单选题
数字系统中,常用()电路.将输入脉冲信号变为等幅等宽的脉冲信号。
A
施密特触发器
B
单稳态触发器
C
多谐振荡器
D
集成定时器
答案:
<查看本题扣1积分>
查看答案
答案不对?请尝试站内搜索
推荐知识点:
何种放线菌可以与植物共生固氮?其形态特征怎样?
重度急性有机磷杀虫药中毒时胆碱酯酶活性是()
腐蚀热油泵的轴采用HT20--40材质。
密度大的原油被称为(),这种原油中有较多的重组分(重油、胶质等)。
As Christmas is coming, there are presents to be bought, cards to be sent, and rooms to be cleaned. Parents are ___1___ with difficult jobs of hiding presents from curious young children. If the gifts are large, this is sometimes a real ___2___. On Christmas Eve, young children find the excitement almost unbearable. They are torn between the wish to go to bed early so that Father Christmas will bring their presents quickly and the wish to stay up late so that they will not miss the fun. The wish for gifts usually proves stronger. But though children go to bed early, they often lie awake for a long time, hoping to get a short ___3___ at Father Christmas. Last Christmas, my wife and I successfully hid a few large presents in the storeroom. I ___4___ the moment when my son, Jimmy, would ask me where that new bike had come from, but ___5___ he did not see it. On Christmas Eve, it took the children hours to go to sleep. It must have been nearly ___6___ when my wife and I went quietly into their room and began filling stockings. Then I pushed in the ___7___ I bought for Jimmy and left it beside the Christmas tree. We knew we would not get much sleep that night, for the children were ___8___ to get up early. At about five o’clock the next morning, we were woken by loud sounds coming from the children’s room — they were shouting excitedly! Before I had time to get out of bed, young Jimmy came riding into the room on his new bike, and his sister, Mary, followed close behind pushing her new baby carriage. Even the baby arrived. He moved ___9___ the hands and knees into the room dragging a large balloon behind him. Suddenly it burst. That woke us up ___10___. The day had really begun with a band! ___7___内应选()
课外体育活动的实施是一个()以为主,()为辅;宏观调控指导,微观自主开放为特点的操作过程。
高速客船驾驶人员连续驾驶值班时间不得超过()个小时,两次驾驶值班之间应有足够的间隔休息时间。
一个电流源和一个二端元件串联时,对外电路而言等效为______。
()问题是教育兴旺发达的永恒主题,是各级各类学校生存发展的生命线。
世界上最早的国际金融中心是()。