Some day in the near future, people will use same language and they may keep or quit their mother tongues. This book is prepared for that day.
Based on Pinyin system the author combined the International Phonetic Alphabet (IPA) of English and Chinese into 47 symbols of Auxiliary Phonetic Alphabet (APA).

The author also worried about the future of science. Most people know that science is based on measurements. To make a valid measurement people must record related event time and event location. That means, to secure our science, people must have a firm common sense of spacetime.

In this book, knowledge is the useful part of history which is ready for you as of here and now, plus your current ability on logic, both of the basic reasoning and the extended imagination. A piece of science is a knowledge comes with formula or formulas. The common sense is the intersection of individual's knowledge in the related area while history is whatever happened in the past, especially those related to human beings.

What are your definitions of knowledge, science and common sense?