题干

关于家庭电路和安全用电,下列选项中正确的是(   )

A:家庭电路中必须安装保险丝或空气开关

B:在未断开电源开关的情况下更换灯泡

C:我国家庭电路的电压值为380V

D:用湿布擦拭正在工作的台灯

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A

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    My school stood in a big square playground in southeastern South Dakota. One teacher taught all grades, first through eighth. Most grades had only two or three students.

    Our school day started with the flag pledge(宣誓). Then the teacher called one grade at a time to the recitation bench beside her desk. She'd check our work, explain the new lesson, and dismiss us to go back to our own desks and do our new work, all in less than ten minutes per grade.

    At noon we ate lunches we had brought. Our lunches consisted of homemade sandwiches and if we were lucky, dessert. My favorite dessert was a fresh pear, and a piece of Mom's delicious sour cream chocolate cake.

    The annual Christmas program was the most exciting part of the year. We hurried through our lessons during December to allow time to practise poems, songs, and plays.

    A few days before the performance, the school board members borrowed equipment from the town and set up a stage across one side of the classroom. We hung bed sheets for curtains.

    On the evening of the performance, petrol lanterns hanging along the walls cast a warm, though not very bright, light over the gathering crowd. We could hardly contain our excitement as we looked from behind the curtains to wave at our parents.

    On a spring Sunday in a new term, just before the last day of the school term, everyone in the neighborhood gathered for a picnic. Our moms set fried chicken, bowls of salads, and desserts on the teacher's desk and the library table. After the dinner, we played games. One of the school board members brought big buckets of ice cream in the afternoon to top off the picnic. How we looked forward to that treat!

    I was just nineteen years old when I started my first teaching position in a country school with thirteen students. I felt excited, nervous and happy as I prepared my lunch bucket the first morning of the term. I can't remember what kind of sandwiches I packed, but I do remember I put in a fresh pear and a piece of chocolate cake for dessert!