题目

文中共有10处语法错误，每处错误仅涉及一个单词的增加，删除或修改。 Once I had to read a text-book which was so expensive for me to buy it. I couldn’t obtain it from the library and an only copy I could find was in a certain bookshop. So I will go along to the shop every afternoon and read a little of the book in a time. One day, therefore, I was disappointed to find the book missing from its usually place. He was about to leave when the owner of the shop waved at me. Expecting to be told off, I went towards him. To my surprise, the owner pointed to the boo短周期主族元素X、Y、Z、W、M的原子序数依次增加，X与Y不同周期，Z的内层电子数是其最外层电子数的5倍，惰性电极电解熔融ZM2可得到Z和M的单质。W的单质一般为淡黄色固体，易溶于YW2溶液。下列说法正确的是A. W的氧化物的水化物溶于水均显酸性B. 能用pH试纸测M单质的新制水溶液的pHC. 原子半径：Y<W<M<ZD. Z单质能与冷水迅速反应得到X单质