选做题：读短文填单词。

     Do you like friends who can teach you a lot every day? Books are 1.s_______ friends because they bring

knowledge to us and keep us company through our life. They are so valuable that 2._______ (图书馆) are

built to 3._______ (存放) them. Almost all great men are lovers of books. Franklin said that it was books that

4.1_______ him to success and that he could have achieved nothing 5.w_______ books. Books are the holders

of mankind's 6._______ (经验) and imagination. They enable us to see through the past and predict the

7._______. So when you open a book, you would get into a world 8._______ you have never beer/before. A

good book is a good teacher that 9.h_______ you to get over difficulties. No matter what you are, 10._______

or old, poor or rich, books are your devoted friends. Love books and love life.

绝缘斗臂车的绝缘斗应具有高电气绝缘强度，与（）一起组成相对地之间的纵向绝缘，使整车的泄露电流小于（）μA；