叶蝉散（isoprocard）对水稻叶蝉和飞虱具有较强的触杀作用，防效迅速，但残效不长。工业上用邻异丙基苯酚合成叶蝉散的过程如下：

下列有关说法正确的是（      ）

4÷9× $\frac{1}{3}$ =____     $\frac{1}{3}$ ÷ $\frac{1}{2}$ × $\frac{1}{3}$  ÷ $\frac{1}{2}$ =____

1.36×99＋1.36=____      1÷ $\frac{1}{5}$ － $\frac{1}{5}$  ÷1=____

如图，经过刨平的木板上的两个点，能弹出一条笔直的墨线，而且只能弹出一条墨线，能解释这一实际应用的数学知识是（　　）

    One day when I was 12, my mother gave me an order: I was to walk to the public library, and borrow at least one book for the summer. This was one more weapon for her to defeat my strange problem—inability to read.

    In the library, I found my way into the “Children's Room.” I sat down on the floor and pulled a few books off the shelf at random. The cover of a book caught my eye. It presented a picture of a beagle. I had recently had a beagle, the first and only animal companion I ever had as a child. He was my secret sharer, but one morning, he was gone, given away to someone who had the space and the money to care for him. I never forgot my beagle.

    There on the book's cover was a beagle which looked identical (相同的) to my dog. I ran my fingers over the picture of the dog on the cover. My eyes ran across the title, Amos, the Beagle with a Plan. Unknowingly, I had read the title. Without opening the book, I borrowed it from the library for the summer.

    Under the shade of a bush, I started to read about Amos. I read very, very slowly with difficulty. Though pages were turned slowly, I got the main idea of the story about a dog who, like mine, had been separated from his family and who finally found his way back home. The dog was my dog, and I was the little boy in the book. At the end of the story, my mind continued the final scene of reunion, on and on, until my own lost dog and I were, in my mind, running together.

    My mother's call returned me to the real world. I suddenly realized something: I had read a book, and I had loved reading that book. Everyone knew I could not read. But I had read it. Books could be incredibly wonderful and I was going to read them.

    I never told my mother about my “miraculous” (奇迹般的) experience that summer, but she saw a slow but remarkable improvement in my classroom performance during the next year. And years later, she was proud that her son had read thousands of books, was awarded a PhD in literature, and authored his own books, articles, poetry and fiction. The power of the words was held.