【实验器材】额定电压为2.5V的小灯泡（正常发光时电阻约为6Ω）、滑动变阻器（“10Ω  2A”）、新干电池两节、开关、导线若干等．

【实验步骤】

对下列句中的引号作用判断不正确的一项是（    ）。

完型填空
      Books are our greatest friends. They 1us stories of every country in the world. They give us all kinds of 2 . Life is short. One can not know and see 3 in the world. 4 the help of books, one is able to know what happened thousands of years ago and 5 is happening in every part of the world now. Books give us not only knowledge 6  pleasure. Reading good books is the best way of7    our free time. And many beautiful stories for children are 8and full of wisdom(智慧).
    All the great men 9 books. Knowledge from books helps them to succeed, because books are the source(源泉)of knowledge and knowledge is the source of  10 .