Nowadays, English exists everywhere in our life, such as English manual, English paper, English meeting minutes, English interview and English communication.

My father has asked me why we need to learn English when I was in grade one of junior middle school. I remember my answer was there are only two languages in the word-----Chinese and English. It was a really stupid answer.

Now the Chinese children start English since kindergarten years. More and more senior middle school has international class which provides fine service for the general students to study abroad.

The problem I have been encountering is how to buy English books. I am looking for two kinds of English books, one is English version of mathematics textbooks in senior middle school, the other is professional English books about photodiodes.

Another problem is that these English version books are very expensive on line selling. I am afraid that it does not help much after spending more than $100 because there are not more detailed contents to preview.